Latency issues? Can you hear yourself through it?
No latency unless you put certain complex effects on it. Then monitoring through your computer will have a bit of latency.
The sound quality is great; it's the same microphone as the regular AT2020, just with a USB connector so it can be powered by a computer. It'd be akin to buying a regular condensor mic and running it through one of those XLR/USB adapter/preamp combo things.
And yup, you can hear yourself. The gain is quite good. Meanwhile a cheap dynamic mic through my cheap FastTrack is extremely quiet; very little power and gain there.
Here's two quick recordings I made with only the AT2020. In the first, I speak for a bit then record acoustic guitar and vocals both through the mic. In the second it's just another guitar+vocal. This was just done in my living room so you might notice a bit of background noise. If you soundproof your room properly I don't imagine you'll get nearly as much. Also I screw up the singing a bit, but it's just to show off the mic, so don't laugh!
http://sixpop.com/files/204/Music/AT2020Test.mp3
http://sixpop.com/files/204/Music/dictionarysnippet.mp3
I did this quick and dirty, though.
The AT2020 is primarily a vocal mic, and I would normally just use it for that, and either mic a guitar amp separately or run my guitar through a preamp then an interface and have it separate. For vocals alone, the AT2020 is great!
I've heard good things about the Blue Microphones Snowball as well, which is a bit cheaper, but after hearing the AT2020 on a YouTube video, I figured it was the right choice for my money!