I have a spider jam. It is a great learning tool. 12 amp models, ton's of presets (supposedly set up by professionally musicians), Backing tracks (drums), songs that you can adjust pitch and tempo then play lead over, built in tuner, 2 metrodomes, mini input jack for cd or streaming music from computer, analog preouts, extra input for another bass or guitar, mic input with effects, 75 watts of power with a 12'' celestion woofer, and many other features.

But what I like about the most is the the recording features, the backing tracks, and the FBV express pedal I bought recently. IE I can record some rhythm save then dub lead over top of it and now with the pedal I can do it hands free not having to mess with the puter for recording or get up and push buttons suits me fine. Also with the pedal I can set up user banks A B C D 1-9 and switch between presets. It also has a volume pedal with WAH (but I can't seem to get the wah to work) , tap tempo and a built in tuner. At first I thought all the backing tracks were a waste, but they are quality recorded by a real drummer Recently I have been recording rhythm over several of them and can really tell if I am in time with the drummer or not.

Far as sound quality hard to determine with my guitar. I can let you know more when I get my new one at the end of the month, but with my setup now, not terrible not that great but plenty of volume. I heard a demo with an XPT700 ( the one I'm buying) thru this amp it sounded pretty good.
As far as the download stuff I have no idea this thing has keep me plenty busy out of the box.

I hope this helps cheers,

Doug