RacingManiac,
As far as I know the old mags are interchanageable with the "new" Glock. Really all that is different for the mag is the bumper on the end (which feels quite fragile, I'm hesitant about dropping them on the ground).
I personally really enjoy it, but as with anything tm it feels extremely toyish. I've never gotten to handle a guarder frame for the TM G17 but for 30 bucks + shipping I'd rather try that than to get a New TM G17 for donor parts, if I didnt live in Canada
A pooper for me though is that they don't come with the night sights that the original did =( I wish there were more optic options for TM glocks.