Feature:
Most useful features: The 8 direct outputs, and the ability to change the sound by "altering" the drum heads, the depth of the shells, and the microphone positions. Least useful - some of the weird sounds that I will have no use for, and it could use a few more snare sounds - I only found one I really liked

Quality:
Well constructed, solid unit. Looks like it could take quite a beating. I've never had an issue with Roland's quality.

Value:
Everyone comments on this - the price is PRETTY STIFF. It certainly is a great unit, but it sure is pricey.

Desirability:
Well laid out inputs / outputs and controls. Sounds can be changed quickly and easily. Cool digital display

Sound:
Compared to the TD-6 I have been using, this is light years ahead on sound quality. The cymbals and drums sound so close to an acoustic set, you would have a hard time telling them apart with your eyes closed. I play in a 70's to 00's rock band, and this works well for me. The hi hat and cymbals are more expressive than the TD-6, and the module is very sensitive to even minor nuances in technique when playing the drums.

Support:
I love Roland stuff. They are always very helpful on the phone.

Overall:
Since this is such a better machine than my TD-6's, I don't expect to have to replace it for a while - unless something a LOT better comes along!!

Sound:
I own a td8 kit but have played the td20 a couple of times... I thought the TD8 was good (with expanded pads such as pd120), this is a whole new level. It felt even more real and the sounds are ut of this world. cymbals seem much more real and the toms (having positional sensing) sound fantastic. I am waiting to buy one of these!