I went through this as well (before I changed the whole blasted thing) and the consensus I got was to vary--if you have diagonal on one, do straight or running bond on the other. But if diagonal makes you happy, do what makes you happy.

Here is a link to google, how that backsplash should have been installed. There are some u tube videos too. I watched one video, where they used grout, between the countertop and the backsplash, and grout should not be used there. Caulking shud be done between backsplash and countertop. My backsplash is also caulked in all the corners, rather than grouted. Once you watch these videos and read these articles, you will see that your thinset was put on improperly, and thats why your tiles are falling off. Please read carefully. https://www.google.com/search?source=hp&ei=uI4VW7HdLszKjwTtrqSoAw&q=how+to+install+glass+subway+tile+backsplash&oq=How+to+install+glass+subway+tile+&gs_l=psy-ab.1.0.0l3j0i22i30k1l3.3755.12143.0.14244.41.29.3.9.9.0.173.3348.9j20.29.0....0...1c.1.64.psy-ab..0.41.3556...0i131k1j33i22i29i30k1.0.70wb9L5GlO8

they sound interesting enough to me, being crackled and having variation. larger size might work..what size you consider? Gray is already considered dated lol. Makes no sense to me personally as all this dated thing is a new concept I'm still struggling with-how a color can be dated? but in terms of what happens in trends etc-it's on its way out, yes. they move into warmer tones. they're still into greiges for now to bridge between things a bit. white is becoming big as a neutral. wood stains are making a big comeback. this update on trends can go on and on but i'm sure you can find thousand threads here discussing it so i'll make it short. if you're really worried-it might be you're simply are not attached to a color enough. which is okay, really. then pick off-white. off white is pretty. Even very much so. I like both off whites and grays(I do have preference for much warmer grays though) so I have off whites and warm grays. And many other colors too since I love them too. I commit by choosing something of course,-but it's fine since commitment, paradoxically, is a road to freedom:) But I admit I was also worrying when choosing..well choosing everything except for stuff like toilets etc. Of course one worries, it's a hassle and an expense and you want to love it in the end. So. Try to worry less. If you can remove "dated" from the equation- great. Go with your heart's desire. If no-then ok, take it into equation and don't do gray. Worry less. You did a great job on everything else, so no reason to think your backsplash won't turn out well either. It will.

Hi Chispa, House is a townhouse built in 1996, trying to modernize the look. As far as decorating style, I like modern/contemporary, nothing too funky. Something that would be cohesive with the rest of the kitchen, and bring the kitchen to life a little. It's very white right now.