I dunno.... I don't really hear any difference when recording direct compared to using an amp, except there's less noise and you can customize the sound directly to the song.

I did this demo ages ago using AmpliTube....

http://s93744050.onlinehome.us/mp3/AmpliTubeDemo.mp3

...basically the first 30 seconds is straight line in, then it's repeated every 30 seconds with a different amp patched in.
If it sounds a little too cold, just add PSP Vintage warmer into the mix.