I used TaxCut once, a few years back. I found it to be buggy, unintuitive, hard to use, etc. But that was years ago, I assume they've improved.
I've used TurboTax since then, and have generally been pretty happy with it.
That said, does it have to load all that garbage?!?
It installed IE5.5, which is OK, except that it decided it wanted to be the default browser (which is not OK).
It also dumped a few more advertizements on my desktop (AOL, Keen, Quicken, etc.).
And then I had to reinstall the 2000 version, and got them all over again!
It's not that big a deal I guess. I've just gotten so far away from that nonsense running Linux that it's really irritating now.