I plug my guitar through a JoeMeek VC1 preamp and an RME Multiface into Sonar 7 where Amplitube is a vst.
My old computer is a P4 2.4g with 1g memory. I can run it at 3ms latency (24bit 48k) plus another 12 tracks of audio and effects before it maxes out. Amplitube will be taking a good 1/3rd of the system resources, so it is pretty cpu hungry.
Sounds are pretty authentic for a piece of software and it's very user friendly. The stomp boxes are simple and can get very good sounds. Like a real Fender amp, just a little tweak anywhere goes a long way. One great advantage of software is that you can also tweak it after the event.
You'll certainly need some kind of pre-amp in. Just a line signal - even from my active EMG's - isn't enough juice.
I guess the only downside of it is that it's absolutely nothing like the real thing in terms of vibe, but for working things out, it's an excellent tool. And of course your neighbours and loved ones will be non the wiser if you're composing all sorts of devil-worshipping songs at 3a.m.
EDIT: Oh there's now and "Amplitube Fender" Ermm... Sorry.. <buries head in hands..>
Yes, I have Amplitude Fender...I have only spent about an hour with it, but it's a lot of fun. I haven't tried it in context of a recording with other instruments, just solo guitar where, like trying effects or 'getting your sound' you know it's gonna be different in a band context.
It's not the same as moving air and getting that super-touch-sensitive thing that happens out here in the analog world, but I think the technology is coming along nicely, it's a big jump from the old Amp Farm of 7 years ago...as Lou said above, it's not the same vibe as an actual amp, but for what it is, it's cool.
There are a lot of flavors (amps and speaker combos and effects) available...I'd imagine in context of a mix, depending on how picky you are, it might work pretty well...it will certainly give you 1st class demo quality and allow you to have fun while practicing quietly.
In 10 years time who knows what technology may bring- they may be able to really nail many more subtle aspects of the complexity of real amps...
I find the one thing the virtual amps can't do is dynamics. Great for all quiet or all loud but they don't cut it if you use the volume knob on your guitar or even simply play harder for certain passages in a song.
I just downloaded the demo version yesterday, so I'm pretty new to it. Mostly I spent a little time comparing it, through Pro Tools LE, with Guitar Rig 3, which I own. So I stuck with the tweed deluxe and bassman and the BF deluxe mostly, as that's what GR3 has.
They actually sounded pretty similar to the other's corresponding model, or at least I could find a setting with each that was pretty close. I think if/when I work with them a little more, I might decide that one is better, but they are pretty close on early appraisal. Of course, the similarity ends when you get into the other amp models, because each has amps and other features that the other doesn't. I find the noise gate/suppression on GR3 works pretty well with tweakability, AF doesn't seem quite as good, but again it's early. I have some free time right now, so I'll be able to do a little recording, and some more comparing, that's why I chose now for my 10 days.
I just do simple amateur home recording projects, btw. I'm inclined to think I won't be buying AF right now, as I can work pretty well with the Fender models that GR3 has and I have already. It would be cool to have both, but definitely a luxury for my level anyway.
I think the demo version is the same as the full version, just won't work after 10 days. Might check that to make sure.
according to some people on the kvraudio.com forums, there are some minor bugs in the AT fender software. not sure what they are on about as i didn't have a chance to read all the posts. you can solve some of the touch sensitivity issues by running the AT software into a tube amp. i am using the stompio and outputting from there to the power amp return on a fender twin. sounds really good to my ears.
samash was blowing out some stomopio's for $399 recently.