Because of the size of the tile, and therefore, the number of grout joints, I wouldn't be worried so much about slippage. Although for the look you're going for a much larger tile would work better, what you're proposing sounds pretty nice.

If you keep your grout color close to the color of the subway tile it won't look too busy. That way you see mostly the texture of the subway tile, and not a grid pattern which might conflict with the floor pattern. You can use a deeper grout on the floor which would be easier to maintain.

I went into a state of panic regarding the Islatile. This morning I drove over to a store where I bought the subway tile and spoke to Bill who is one of the owners and a great guy willing to give information. He loved the floor (even though I bought it at Cancos) and thought it would love great. He said Isla was a good name and made a quality product. I am going with a biscuit color grout on the subways and as blondelle said it would look mostly like texture and not conflict with the floor. I am leaning toward a medium taupe grout to pick up the color of the one inch square. I thought I read on the forum that the grout on the mosaic would help with a glossy finish. I am having the bathroom gutted and am going with the Kohler Memoirs "Stately" pedestal sink (24"), toilet and bathtub.

I just looked at the Isla tile you wanted to use. There's a matching 10 X 16 wall tile that's less than $4 a sf. that I think would look much better than the subway tile. I would use that in a brick pattern Why didn't you want to use that? There's also a beautiful matching carved listello I would use with it.

Blondelle...I am committed to the A.O. biscuit subway tile sitting in my garage. Bought and paid for. I did see the matching 10 x 16 wall tile and the listello at Cancos after purchasing the wall tile. I am not crazy about such large tile so I am okay with the subway. I was considering the carved listello but I did not care for the colors in the listello field. I may take a sample home just to try but at $33.00 each I would really have to be crazy for it. The Isla vanity series is gorgeous. I am looking at a pretty leaf pattern listello in biscuit and am waiting on two samples from A.O...or maybe a biscuit chair rail.

Subway tile is a classic and it's often paired with a basketweave floor. Both would look really nice. Didn't know the listello was so pricey. The larger tile is more modern but looking at your original post I see with choosing the Memoir Kohler series, you're going for a more traditional look, and the subway is better suited for that.

The listello doesn't look that price. That's way too high. A matching one in biscuit would be pretty with it. You might also look at a thin liner tile in the color of your floor dot to tie that in, and maybe a darker baseboard tile in that color. Please post a photo when finished. Love to see ;-).

The listello is too pricey for something I am not mad about. I just got back from Home Depot and picked up a 3x8 listello in HD's Eliane line. It is bisquit ground with a scroll leaf design and a subtle deeper biscuit running through the ground. The listello picks up some of the colors in the floor tile but is slightly off against the square. The square is in the taupe family..not a perfect match to the taupe square but it could work since they are not next to each other. The listello is 3x8 and priced at $2.99 each. I will try to find the name of the series from H.D. Maybe you can take a look. I will post pictures. I just bought a new Cannon but not sure how to use it to post to the net. Thank again