Regarding shipping, I ordered just before or after I posted, on a Saturday. They said it would be here Monday. It was here Tuesday. So 3 days instead of 2 (I have Amazon Prime).
The case fits but not completely. The bottom part fits like a glove. There's no mistaking how it fits in. Perfect fit. However the lid (the dot view part) does not close all the way. I have nothing on my screen, not even a screen protector.
The dot view gimmick is just that. You can swipe on the case but you have to really press. You might be surprised by how much pushing you have to do. You can't change the theme. You can't customize a thing about it. You can change the temperature units in Settings → HTC Weather. This is not very intuitive and it's not stated anywhere in the manual.
The magnet thing works great. When you open it, the screen comes on. When you close it, the phone goes to sleep.
Dark grey means grey that is not light. I wouldn't call it dark, either. It's just grey. It's similar to the gun metal grey finish of the phone (if you have that option — I do, except stupid PC Verizon calls it "metal grey" since "gun" is a bad word now) but matte, not glossy. And it extends the premium feel of your phone. It feels like a premium product. It feels like a genuine HTC accessory.
It does leave dot view smudges on your screen, but these are easily wiped off with a microfiber cloth, which every phone owner should have, anyway.
You can forget about one-hand usage. You will need the other hand to hold the case open while you text.
I use a FlyGrip and I have their case. The FlyGrip would not stick to the bare back of the HTC One M8. I don't know if that's because the adhesive doesn't bond to metal. It's peeled off my naked Samsung Galaxy S3 and two of its cases cleanly, so the bond is not permanent. I might try attaching my FlyGrip to the Dot View case, but what would be the point? The FlyGrip is made to accommodate one-handed phone use. Dot View prevents it. And with a FlyGrip, you gain a kickstand, but you just can't lay your phone flat on its back.
So now I have two cases, and though I meant to take the Dot View case to work, I just didn't bother taking my phone out of the FlyGrip case. I intend to keep the Dot View case, but probably won't. I have one IRL friend with a One M8, and I might let him try it out, but he only uses his phones naked. He doesn't like cases at all and thinks they're a waste of time that take away from the engineering of the phone — especially a nice one like ours. And I don't disagree, but I like the FlyGrip's utility. It's useful to me. It prevents drops. But it isn't cheap.