I just got this delivered today, and was itching to try it out after a 2-year battle with an M-Audio Fast Track that refused to work properly.
At first I was worried when I plugged the cable into Windows 7 and there was no new device sound (though the blue power light came on straightaway); however when I switched USB ports it was fine, so I'm guessing that port was just a bit temperamental.
I've tried the device in Ableton Live today, and after realising it was my guitar volume that was making the output so quiet (slight blonde moment there, lol), the cable worked perfectly; it was recognised instantly by Ableton and only needed some very slight tweaks to get the best output (and considering that I'm no music recording expert, that's a very good thing). The sound quality is excellent, even with my guitar's single-coil pickups (I have a Fender Squier Affinity Series Strat); in fact the only time I got any unwanted noise was when using certain noisy effects, and even this could be remedied by tweaking the effects themselves.
I did have some latency, but to be honest, this isn't a real worry for me; I was expecting latency on a laptop and I know what actions to take to reduce it. Today was just a test :)
All in all I am extremely happy with this product, as it means I can finally record decent-quality guitar; now I can finally make some songs! I've already written a glowing feedback message to Lindy, and I would thoroughly recommend this product to anyone who wants a quick, easy and quality method of recording guitar on a pc.