I tried the training mode tonight and was disappointed. The soldier's shooting range was a good start, but I'd have liked to have had it go on to show the basics of rocket jumping. And have a similar training range for each other class that teaches you how to use its signature weapon.
I want to check it out, because me playing TF2 is comedic, and not because of my FPS skills (which are rusty, but I did play competitively years ago). Stuff like tricks for each class and map hints/walkthroughs would be more useful than target practice for all but the most total newb. How to lay out engineer emplacements, sniffing out spies as a pyro, proper sniping techniques, etc. There's so much more to playing fps than the actual shooting.