Sound — 7
This pedal recreates the sound you put into it perfectly, so the tone will depend on your personal setup. The only issue I have with sound is when playing with distortion. I'm running guitar-pedal-amp, so when I have a drum loop playing, I have to use a clean setting on my amp, or the drums become a mess that drowns out my guitar. It has a loop quantize function, meaning if you record something and are slightly off time, it will fix it up for you. In my experience, it isn't all that effective, and sloppy rhythm will still be noticeable.
Overall Impression — 9
I use this pedal whenever I feel like jamming, and it works great. It is very easy to use, takes no time to set up or program, and has a great selection of drum samples. Cleaner styles of music work better with it, as the drums retain clarity more effectively, so I would not recommend it for looping distorted riffs. I received it as a gift, and it has been an excellent addition my gear. It is perfect for writing your own songs, as you can hear what multiple layers would sound like without requiring multiple guitarists in the room.
Reliability & Durability — 10
A tank couldn't have been built better than this pedal. It's compact, and easily able to withstand being jumped on and dropped. Most people, like myself, will just be using this at home, but if I had reason to take it to a gig, it would be just fine on it's own. The adapter works well for when it can be used, just be sure to have some extra batteries around, as they will run out quite quickly.
Ease of Use — 10
The Boss RC-2 is an incredibly easy to use pedal. It has a simple stomp-play-stomp method of operating which makes it fun to play around with. A quick review of the manual will give you all the information you need to know, and can be referred to later if needed. Once you have recorded a main lick, it is easy to loop more over. All you have to do is step on the pedal again and it goes into an 'overwrite' mode, which adds whatever you play on top of the previously recorded sound. If you mess up on a loop, a quick double-stomp of the pedal will erase the latest recording without undoing everything. You can save your loops on separate tracks in order to access them later, and it has separate volume knobs for drums and your plugged in instrument.