I was looking at a a Spider IV yesterday, the 120 model. 16 good sounding amp models (well up to a plexi and then I quit), all the effects you could need, loads of memory locations, 2x60 watts into 2x10" Celestions in a small package and good price. So what was there not to like? The larger floorboard was 60% of the cost of the amp and you need one of them to even use some of the deep editing functions.
This is actually my amp of choice for best bang for the buck. I purchased one about 2 months ago with the floorboard. I agree...a $399 amp and a floorboard that runs about $269 is crazy, but it is well worth it as the new floorboard allows you to download firmware updates which previous versions of the Spider did not have.

The Spider IV 120 is really an amazing sounding amp, and I always looked at the Spiders as "beginner's amps" in the past. I bought one without even trying it first (which I seldom do) going by the good reviews the amp has got so far.

I'm VERY pleased with the tones of the various models as well the ability to update the firmware. All of the models sound great with a strat too which was a selling point for me. I rarely use the insane and metal settings.

The amp is so full and warm sounding (not brittle at all) that I rarely use my Valvetronix amp any more.