oh yeah, buy one. totally worth the money; mine actually paid for itself in two weekends playing chilled out muzak in one of the nicer restaurants in my city. really simple to use with the 2 pedals and the reverse function is probably the coolest thing on my entire rig.

try experimenting with different rhythm patterns/loops and reverse them and record something over it and reverse it again...you follow? just see how lost you can get in your loopy madness. it's an amazing practice tool as well. i've been working on my modes (dorian!) with "Black Magic Woman" by Santana.

buy/rent/build/steal one. whatever it takes because the rc-20 is totally worth it.
I love mine. Invaluable practice tool, and helps composition if multiple guitar parts are involved.

The only thing I dislike is the volume level of the metronome and the lack of an on/off switch (have to unplug the AC and input every time). The volume of the drum kit doesn't scale right at all. Goes from 1 (tolerable) to WTF TOO LOUD at 1.5+ on the dial. Maybe a defect *shrug*