I just got mine into Wraith's tank yesterday, so this is a very early review. It is heating up his tank slowly and it's a nice, small, compact size, which I like.
My only complaint is that the setting control dial seems to be completely uncalibrated. I set it to 81 yesterday and it only warmed my tank to a very steady 76. I reset it this morning to 85, and we're at a very steady 78, according to my thermometer. I searched the web last night and found many others with the same problem, so take that for what it's worth.
Either way, it's a big upgrade over what Wraith had before, so I'll take it. And now that I know its temp control is, uh, quirky, I'll know to keep a close eye on that too.