Well, I've got the CF version, which only has two inputs, which kinda sucks because if I want to have more than, say, two mics on drums, I have to do a submix, and then I can't mess with it after tracking. Of course, the HD has four, so that's not that big a problem with that one. Also, the effects kinda... suck. Like, a lot. The reverbs and delay are very metallic and cheap sounding, and you can't really mess with the settings a whole lot. It has "amp and mic" modelling, but they don't really do much to the tone of what you're recording. It's not too bad for what I'm doing now, which is basically just using it to record vocals and electric guitars, and then put them right on the computer to use them with programmed drums -- but then, I'm really only doing recording for one industrial act right now.
If I might make a recommendation, though, I've also tried out the Zoom-made equivalent, and it was a lot more intuitive. Not that this one wasn't, really, the Zoom just felt better under my hands, if that makes sense.