How about adding an accent liner or accent tiles to break things up a bit if you think the larger gray tiles will be too strong? Maybe just a little bit smaller tile?

Have you seen Kitchenkelly's backsplash? Dark gray and WONderful. I could see a larger rectangular tile looking just as great.

Can you buy a few of the tiles you love and mock up a section (tape them up or otherwise put them up temporarily) to see what you think? Is a bit of last minute fear making you doubt your instinct, or is your instinct telling you this isn't the right choice? Maybe that's what you need to determine...but maybe that's easier said than done!

Best wishes. Your kitchen is gorgeous.

Here is a link that might be useful: kitchenkelly's kitchen w gray backsplash

Hey,
Have you considered glass tiles? That would give you less pattern but the shine would keep it from being flat.
BTW - I don't see gray as working best with your floor and counter. You may want to try a gray paint sample on the wall to simulate the tiles and see how that looks. Of course, you could photoshop gray for the backsplash on your pics and see if you like it then. I'd rather see a more pewter-like color that would add a hint of gray but be warmer at the same time.
My first instinct would be to try a bone color for the backsplash with accent tiles in the same color but with some texture/3D pattern or different shapes to add just a little interest.
HTH

Our cabinets are very similar, and I've choosen to use a glass tile backsplash in colors that compliment my granite. The tiny tiles in the middle are not black, but when installed will be a dark-ish/colorful iridescent. These are from Oceanside. Install is tomorrow!

Imo, I actually think you need a cooler balance in there.

See perched on your hood, four small jars near the middle. The one on the very left, a light sort of aqua? I don't know how that jar looks in real life, but in the picture it gives a beautiful watery tone.

I could see the below baby subway tiles in vertical falling like water down your walls. They would be just a gentle yet interesting background - and definitely not too masculine. Putting them vertical would mirror your door pull bars and the hood chimney. You could even stud them with a little black glass tile in one inch squares if that's not too busy for you.

If the aqua glass is too flashy, try a ceramic in a light, almost white, sage green because I see your tea pot and another item in that color.

But, in any case, I really think you need a cool and gentle respite from all that great warmth and linear lines.

Here is a link that might be useful: Weatherly Tile & Stone, Inc. showpiece

I think a very flat large-format grey tile that looks sort of like cement would be *fabulous*. Or, something along the lines of KitchenKelly's like RHome posted -- In any case, I think the texture and pattern should be very, very subtle -- almost monochromatic and monolithic in appearance.

Masculine? Sure - but only in the sense that it's clean-lined, minimalistic and sophisticated.

Something more 'feminine' or busy would definitely tone down the overall feeling of your space from sleek and subtly rich to more neutral. Is that what you're aiming for?

Thanks all. I think I really am looking for something simple, not outstanding and something that will blend nicely without shouting, "Look at me!" Subtle is best in my book and I think the countertop speaks loudly enough. I couldn't think of or find any other "colors" or "textures" beside the darker gray that would do just that. It was late when I posted so I forgot I had pictures of the tiles, duh, that helps huh? I think the minimalist idea but not harsh and stark and cold is what this kitchen needs. I wasn't thinking in terms of feminine just with so many darks I didn't want it to appear at first glance that many men lived here, (although three out of five do!!). They really could care less anyway, just strive to make the mom happy. What a blessing! Anyway, try to imagine a 7x20 tile laid lengthwise with about 1/8 in tiny bit deeper color grout. Now what do you think? Without the tiny tiles inlaid. Remember: Place them lengthwise in your mind and keep in mind that EXPO uses flourescent lighting and I have lots of overhead lighting plus zenon undercabinet lighting. Thanks again!

I think that grey is the right color and it would work and it would make the counters really pop. What about something other than tile - like stainless, but with a texture?

I've actually looked at some stainless including subways, large pieces with a subtle texture but thought it just might be too much stainless all around and just a little boring. I also looked at a pewter/stainless type in large spans like this one I am looking at but it changed in the lighting so much from a much brighter to darker look depending on the light. Strange. I think that's why I am looking at the gray; in the same tones. I might have to purchase a few things and just start placing them up to actually see.