Be happy to help State,
I'm quite a newbie myself (though I've been researching alot) and I gotta tell you, this thing is easy as pie.
You don't even need an existing sound card. The device is esentially an external sound card. You would continue to use your existing card for games and stuff though.
I think it sounds great, I was blown away by how good my recording sounded. Of course, I'm not a sound junkie like alot of the folks on here, but I'm confident you'll be pleased with it.
The device itself is very user friendly. The software is harder to figure out than the device. I read the manual (I know, crazy huh) and was on my way in no time. I just got it Monday and I just put the finishing touches on my first recorded song just a minute ago.
Your machine should be good. I've got an AMD 1.8 with 512mb RAM. Worst case, you might need to add more RAM but I don't think you'll need to. Just don't run any other programs at the same time and make sure all the crap that runs in the background (like instant messengers and the like) are shut down.
Since you've already been recording, I suppose you already have mics and stuff. One of the reasons I bought
the US-122 is because it has phantom power built in (all I've got is the us122 and 1 mic).
Hope this helps!
J7B