My wife's HD7 has some trouble with photos, though I'd say it's negligible compared to our old Motorola Droid 2 phones. It seems that Microsoft forced the manufacturers to stick with a minimum standard of quality in their components (not just specs, but quality of the parts used), so that the phones would cost a bit more than new Android phones, but actually work well enough in comparison.
I found when using her phone that making sure I held down the button for a sec first to let it acquire the focus level is good general procedure for taking pics. After the autofocus gets a lock, the second click of the two-stage camera button will usually come down pretty smoothly. If only these little LED lights did a better job in low light to help capture the photo and not just blind everyone in the room lol. Guess that's what I get for having high expectations ;-)