As I understand, fruity loops is not the best software to record a live imput like, for example, the guitar. I do use amplitube but use it in Cakewalk guitar tracks. I've start using fruity loops for not so long now ( still trying to understand it
) but I use it only for creating drum loops.
As avalon mentioned, you need to see the graphical aspect of the plug in, once you see it, it's easy to handle since it's like an amp, with a variety of stored presets, amp + cabs simulator, some pedals.. stuff like that.
Im not sure yet how far can you go on FL to record a guitar let's say.. but not sure you have the same features as sonar or guitar tracks ( or any other audio editing software ). I think FL becomes handy once you have the track of your guitar in a wav or something...
Guys, please correct me if I am wrong, but I think you will need something like guitar tracks or any other programme ( already mentioned in one thread, look under "Home recording" ) to get a full view of what Amplitube can do.