i can't say anything about the headrush, but i just got an RC20 (thanks lbanks!) and it is a great first looper. the prices will probably be going down thanks the the RC20XL, so you can get a cheap one soon. the rc20 is really easy. you just hit record, play your loop, hit the record button again, and there you have it! i really like the auto-start button, you press it and hit the record button, and it waits for you to start playing before it starts recording, for a perfect beginning (after about a day, you'll be making good loops) The only holdback, which is corrected in the XL, is the undo button, which isn't a necessity for me, because then i have to to play it right the first time!
Charlie