Re: Thoughts on the Spider II series??
I've played one a couple of times, and for the money, yes..a good amp, IMO. A little "thin" and sterile, but again for the money, it's decent.
However, I would look at the Behringer V-Tone analog modeling amps. The GMX212 in particular. Not quite as versatile as the spider maybe, but I feel the analog modeling sounds more "tube-y", and the cab simulations really help to get a "real" amp sound. Plus it's a bit cheaper than the Spider II (though the durability on the Behringer's seems to be a hit or miss proposition).
The Vox Valvetronix models are really nice too, I have the 50 watter, and am prolly returning it just because it cannot give me the sound I desire personally, but it's the best modeller I've heard yet....the tube power amp really helps. I paid $360 for the 50 watter, and the 30 watter is in the mid 200's $-wise, I believe.
Don't know what kind of sounds you are looking for but the Valvetronix's Vox, Botique and Fender models are the best sounding. The dumble clean is phenomenal as is the Bassman. The Marshalls sound good too as far as the gain structure is concerned but they just don't have the "sparkle" of a Marshall (tube or solid-state). The Soldano (US High Gain) mod, IMO is not very good and the worst simulation. The real Soldano's I've played through and heard were not nearly as compressed sounding. To me it sounds more like an old Boogie..MKII or such.
Good luck...lots of choices out there.