That looks fun - but pricey enough to put me off, and I don't think of myself as especially price-sensitive for such things. A cheaper do-it-yourself alternative is this package:
http://ggww.stanford.edu/NGUS/lpl/which we have. DS7 hasn't so far had much time for working through the book (though he has encountered much of the material elsewhere) but he loves playing with the software, Tarksi's World especially. NB it has an auto-grading facility which seems to work (you do some exercises and send them off to their server which marks them) so it's not *totally* do it yourself.
