Feature:
There is really nothing else on the market to compete with this, in terms of programmability, expandability, and flexibility. This may seem like a small thing, but for me it was critical: you can run this guy on batteries. The only comparable product on the market is the Behringer FCB1010, which has the great advantage of being being dirt cheap, but which requires AC power, and which is much harder to program IMO. The FCB1010 is great value, of course, but the FC300 is much easier to use, and eliminates a power cable on stage. If anything the features are *too* extensive for me, because I only use it one mode, but it's a mode most other products don't support: CC messages (versus Program Change, etc.)

Quality:
It's a tank. The switches (the Roland standard) are silent but provide enough resistance to keep you informed as to what's happening at your feet. It's heavy, which has its pros and cons. I wish there were a smaller version available - perhaps with one pedal and fewer switches, but until then this is it.

Value:
The product is very expensive, and hard to justify when a product (FCB1010) with just a couple of comprimises is SO much cheaper. But when those few comprimises have been nagging at you and you realize you've been searching for something better for YEARS, you buy this. I was lucky enough to find a cheap one, but all the same, I wish I'd just bought a new one earlier. The time saved would have made the expense worthwhile.

Desirability:
It's not an especially innovative product, it's just the only one on the market that isn't broken in some way or another. Its big (overkill much of the time) and it tends to eat batteries, but its perfect otherwise.

Sound:
n/a

Ease of Use:
The interface is complex, owing to the flexibility of the product, but there is good feedback via the display, and dedicated buttons for most functions (versus the typical "hold down pedals x, y and z for 23 seconds" nonsense), so I rate this a 9. And if it were any easier (i.e. a 10) it would probably rank lower in "Features".

Support:
Unknown, really. But this product has been in production for a long time and is well-documented, so I feel pretty good with my odds if I ever need support.

Overall:
It's simply a keeper. Until something else hits the market, this is the one. If/when it dies, I'll buy a replacement. I've considered buying a 2nd just to have one in a different room.