Short answer... yes... I use it, I think it's great, especially for a first-timer like me. The track is nearly bulletproof, and while a bit more expensive on the outlay, it comes with switch motors built right into the turnouts.
While I haven't done it yet but will be doing within a few months, it can be painted, weathered, and even ballasted beyond the roadbed appearance...
Also, with a little care, the track can be built in such a way that looks a bit more organic rather than simply straights and turns. The nice thing is that you can build up and take apart to suit your needs... you can run trains on it even before you finalize it by gluing it down.
Here's a link to my in-progress thread for my layout which uses Unitrack:
http://www.the-gauge.com/showthread.php?t=23681
I've done a bit more since these pictures were last taken, so it's time for me to try and post something new soon.