You don't have to have a change in height to use two different countertop materials on the island. If you are worried about a seam looking obvious; why not use some BB (end grain is my fav) on one of the ends. I love that look!

Thanks so much for the input remodelfla. I remember seeing one particularly gorgeous kitchen here that did that, but I can't remember the name - white cabs, walnut BB - rather formal. I loved the look there, but it just doesn't speak to me - if that makes sense. I think I have gone loopy with house decisions :)

Perhaps it was this kitchen....I pinned it because I liked to option to extend the island without a seam using the Boos block at the end near my range.

Here is a link that might be useful: Walnut/Marble Island

michelleDT - that is it! It's gorgeous, but not really what I am looking for. We are planning on something a little simpler and more casual. I think we will either stay at 10' max length at all one height or add the bookcases to allow for a little more flexibilty. Just not sure which one? Opinions?

I think Butcher Block lends itself to a more casual look, so I think it might work for you. However, if you don't like it, then don't do it! (I'm not a fan of BB counters either, but I can appreciate them in other people's kitchens.)

Why are you so worried about no seam in your counter? If done right, seams should not show much, especially in a straight run and a uniform color (much easier to match the color). When selecting a fabricator, check his/her work at actual installed sites - in particular, residential homes.

buel - the seams that I have seen in large, single-level islands have been really obvious and I think it would drive me crazy. Maybe I have just seen poor examples???

The seam in our current perimeter counters doesn't bother me at all (eventhough it is noticeable), but it is in a corner which seems like a natural place for it. I just think a big seam down the middle of a slab would jump out at me.

I am just having a hard time with the island in general - how to work in everything I need, how big is too big?, how to make it not seem like a giant box in the middle of the room... there are so many gorgeous kitchens here that I may have just lost perspective.
Thanks for taking the time to post. I always appreciate it. I will check with my fabricator as you suggest.

We shortened the length of our island to accomodate the maximum slab length available in the stone we wanted. I would make the same decision again, as even the seams in the perimeter are noticable to me and I would not want a seam in my island. If I really needed a long island to accomadate two DWs, which makes sense for your family, of course,I think I would use silestone quartz or glass composite on the island only.

Honestly, I believe it depends on the skill of your fabricator. Here is the seam on my island/overhang and I literally had to search for it to take the picture.

remodelfla - Thanks for sharing - that is a beautiful stone - what is it? I guess it really depends on the fabricator. We considered getting soapstone from FL Joshua and then I would feel much more confident, but the soapstone was a huge step up in price and I just couldn't justify it.
I will have to look at some of my fabricators seams and decide.
I guess that means you are against the bookcase idea?

Well... mine is Monsoon Wave soapstone fabricated and installed by Florida Joshua. He didn't stock it at his yard so I flew up to Jersey (incorporated it with a trip to see both my boys who live in NY), picked out my slabs, and had them shipped to Joshua. I live in So. Fla. so he had to take a couple of trips down here to measure, fabricate, and install. It went perfectly and even though it was a HUGE splurge for me; I would do it again in a heartbeat. It is beyond functional, beautiful, and takes a beating without issue. I can go without waxing for a couple of months and fall in love with the kinda washed black denim look of it. Then I'll get in the mood to shine it up and fall in love again with the vibrant sea glass colors that run through this stone.

If you have the chance to use Joshua... it's worth every single penny and more.

It looks like your sink is directly opposite your cooktop. If more than one of you are in there at a time, this might be a problem. Could you reconfigure the island to slide the sink up "north" enough so they clear each other?

Chibimimi - I learned that having the sink directly across from the cooktop was a no-no here and I looked at moving it, but with the dishwasher on each side of the sink it really doesn't move far enough to be offset - if that makes sense.

We added the second sink on the oven wall because of that - so hopefully that will solve the problem.
Thanks very much for looking and pointing out any problems you see. I definitely want to know of any potential problems!