i use the rio cali 256 as well, and this is a good choice because i bought it for running, and the armband is good enough for that. it works well, in general. the radio is shit, of course. i don't even come close to filling it up, though...i never have enough mp3s on hand. also, i don't use the armband these days, just put it in the pocket of my sweat pants since it's too cold to run with shorts, but that's neither here nor there and quite frankly i'm not sure it's anyone's business. maybe not even my own.