I had a 12m Aero II for a couple of years. Learnt on it and all that jazz. Great kite.
I bought myself a Torch a few months ago and there is a noticable difference between a kite that is a couple of years old and the latest models.
I find the Torch much more stable and predictable than the Aero; it handles the gusts a lot better and the power is much smoother. However, if I hadn't of bought a newer kite then I wouldn't have been any wiser!
But if you've got a good deal on the Aero and aren't really looking at spending mega bucks on the latest models then I'm sure you won't be disappointed.