Hmm... I have one, a Remington Wet 2 Straight straightener. It's nice because it has 30 heat settings, and it tells you which settings to use based on your hair type and how wet it is. However, my hair is wavy and a little thick/coarse, and I have a hard time getting it dry and straight unless I go over each section a few times. Might work best on towel-dried hair. It probably cuts down on styling time, but is it worse for your hair? I don't know. It makes a loud hissing sound when it releases the water as steam, which is kinda weird, LOL.
I'm also curious about others' experiences with them, though.