It looks like an interesting plant and if the price isn't too high I would say go for it if you aren't too high up in the hills. Portland is much warmer in the summer than Western Washington, but winter lows can get really cold. With Arctic air coming down the Columbia River gorge much like the Frasier River does north of Western Washington. Hoyt Aroboretum is on a hill top right in line with the river as it comes out of the gorge so gets the full blast of cold air so I wouldn't let that be the judge of your success or not.

The cultivar is a Monrovia item and the current delivery is a 5 gal pot for $75 (if all local vendors who got it have the same pricing). Its foliage is spectacular but the flowers on the stock I saw looked like they had tissue-like, delicate petals that might be apt to melt in rain. And the buds were near the bases of the shoots, the flowers kind of hidden among the leaves. However it is perfectly possible that older growth on more developed, less vegetative examples displays these better (many kinds of trees have an apparent youthful phase where growth and development dominates their structure and an equally visible mature phase where much of the emphasis shifts to flowering and fruiting).

As mentioned the Willamette Valley is subject to cold air coming down the Gorge, with record low temperatures at weather stations in larger communities all being subzero - and this actually gets worse as you go south, with the Springfield-Eugene end having had -14F to -17F. Whereas the U.W. weather station in Seattle bottoms out at 10F - there is no inland sea in Oregon.

By the way Woodinville is a notorious frost pocket, based on what I have seen in Orlando (USDA 9) - where I saw the American Gordonia growing wild - this item may need sandy soil and a south wall in Ballard or West Seattle etc.

With heavy summer watering.

The Hoyt planting freezing off* during a time when there has been hot water in the North Pacific affecting the regional climate is not at all promising.

*Assuming that yes, it wasn't in fact vandalism, rabbits or drought

Yes, it is the Monrovia's cultivar. And I agree with the flowers being tissue like. They do seem to handle the rain well but they are not very long lived and drop only few days after opening. I'm hoping for a progression of bloom because my three foot tall shrub is loaded with buds ready to open. The growth is very dense and indeed hides the blooms. I'm wondering if skillful pruning would help display flowers better.

My main concern is hardiness. I do have a sheltered spot next to a wall but it might be a bit too dark for Polyspora if it needs any more Sun than Camellia japonica that I used to grow there in a pot. I do plan mulch it heavily and throw a frost cover if we expect frigid weather (which I hope we won't have this coming Winter). Lowest temps ever I observed in my yard was around 10F and it was indeed in a frost pocket where cold air sank and couldn't escape. I will plant my Polyspora nowhere near that spot.

10F is the all time record low for the one Seattle weather station (0F at the international airport, in Tukwila), recorded many years ago. The fact that you have seen 10F - presumably much more recently - shows how different it is out where you are. As I remember it they were claiming readings like 0F for the old Garden Valley Nursery, which was near where Home Depot and all that stuff is now. (To some extent there seems to be a basis for figuring that at this latitude a location 10 miles east of the Sound will be about 10 degrees colder than one near the beach, but of course this will vary with topography and other factors - look at the difference between the UW and Tukwila readings). Their rhododendron collection was up on the hillside where the air drainage must have been considerable, I don't know if they had their thermometer(s) up there or on the flat in front, where the buildings and plants for sale were. It is too bad the rhododendrons ended up on a south slope, which is totally the wrong exposure for them - and they looked like it, despite some shading from scattered existing trees that were retained.

I saw 10F during my first Winter in this house in 2007. Since then we did have freezes including a solid week of around 20F in December 2013 with occasional drops to even lower. I remember one morning when I volunteered for King Co. digging out native plants in Snoqualmie Valley for conservation purposes. It was 14F and we all looked like Michelin man bundled up to our ears and trying to dig plants in solid frozen ground. It was so miserable that it was funny :-)

I remember the Garden Valley Nursery and the red barn. That's where I took a test to be a Certified Nurseryman and Landscaper in the 70s. Yeah, it's a frost pocket.

Saw this yesterday with open flowers apparently more or less undamaged by recent heavy rain and wind. However the tops being covered with new growth in November is a hallmark of a plant that is not northern adapted.

Embothrium, mine also has this fresh succulent new growth. I guess my plant just arrived from California right before I bought it. I had a chance to talk to Dan Hinkley few days ago and asked him how to proceed. He admitted he lost his young Polyspora when a very early frost hit few years ago. He strongly advised against planting it now so I guess it will spend its first winter indoors as I do not have a heated greenhouse. It might also stay in a pot indefinitely so I can move it freely in and out of a garage.

Mine survived its first winter in an unheated garage. I do not think it will be blooming for me this season as I can't see any buds forming as of yet. Also it became a victim of root weevil attack (characteristic notches on the edges of leaves) along with some of my prized species Rhododendrons. I think it will spend another winter in a garage and in spring I will find a permanent spot for it in my yard. Few weeks ago I saw a nice plant in bloom at Mcmenamins' courtyard in Bothell.

Related thread. She had caterpillars on hers.

http://forums2.gardenweb.com/discussions/4275420/polyspora-full-moon?n=7

I planted one of these in my front garden in Edmonds on 9/2/16...it sure is purdy! Newest leaves are red, all leaves are super glossy (but not as glossy as my Viburnum awabuki 'Chindo' planted nearby) and it has 15 flower buds, some of them appear to be close to popping.

Updates:

My Polyspora did not bloom last fall (though it had a lot of flower buds, those were all killed), it was about 90% defoliated by late winter and had several dead branches, but is now leafing out again, even at the very tips.

I also saw the recent Eucryphia posts here and my Eucryphia 'Restrevor' nearby (planted 8/21/16) came through the winter just fine, no defoliation and it's leafing out normally.

Viburnum awabuki 'Chindo' was completely dead by mid-winter.

By this point I've now seen damage to examples of the Monrovia Polyspora that were kept over under glass in this area. It's spelled Eucryphia x intermedia 'Rostrevor' after Rostrevor House, County Down Ireland. I haven't seen what could clearly be winter burning of any eucryphia in this area this year. Except perhaps to some new and small specimens of the recently-on-the-local-market variegated cultivar of E. lucida planted on the south side of the pool house at the McMenamins Anderson School resort in Bothell. Since the Bremerton E. x nymansensis 'Nymansay' has been said to have look normal a year ago and it was also reported this week the planting site was soggy the 4 ft.+ of rain we had since October was probably why most of its leaves fall off. This is not that much of a departure from my theory that the College had allowed it to dry out since buying the property. In both cases it is a matter of the condition of the top reflecting moisture-related problems for the roots.

Maybe your 'Chindo' got too wet also.