Well, I goofed up my question completely when I said I had an Atom 330:  I had forgotten that I waited until they made these little computer boxes with an Intel D510 which is quite a little boost in performance.  Indeed, with this D510 and 4 gig of memory and a dedicated graphics co-processor, it looks like the box hardly breaks a sweat when my daughter uses it in recording mode.  The processor is typically using 28 percent or so, and only blips up to 50 or 60% when loading a piece of music (not while actually running it).  I am confident that I will be buying a similar computer for the office that will meet our projected needs.

As for the SmartMusic product itself - my daughter finds it "awesome", and I would have to agree.  I may break out my dusty trumpet and try to become a musician.  We may have received the full value of the annual subscription in 1 evening.