ive been using a cheap usb guitar link on an old pc for last few years and aside from it being painful sometimes I can get great sounds from it via software (overloud TH2) and out of my amp.
yesterday i picked up a Tascam US -2x2 (retails over 200) assuming the performance would be far greater. so far trying various drivers and settings i cant get anywhere near the sound quality of the $20 usb guitar link.
the tascam cost me $95 2nd hand, so far disappointed