I was fortunate to have been in a club which had an L-33. I found it to be a joy to fly. The cockpit was comfortable, and it had great visibility and control harmony. If your son is solo in an L-23 or Grob, he should have no problem with an L-33. Of course, with it's lighter weight and shorter wings it is more nimble. It requires a little more care to maintain proper pitch attitude, almost like flying a single seat glass ship.

There are really no serious "Got ya's" from a flying standpoint. I intentionally stalled and spun the L-33 many times. Stall and spin entries were predictable, as were the recoveries. Nor were the stall or spin entries abrupt or without warning.

One thing to be aware of is that the spoilers are extremely effective. Trying to flare with full spoilers and low airspeed will likely mean banging down hard tail first and putting creases in the tail cone just forward of the vertical stabilizer.

Tying down all year is just fine. Of course, like anything else left out, the weather will take it's toll. Be aware that the pin that holds the horizontal stabilizer needs to be taken out more than once a year to be cleaned and greased. Otherwise, it can seize. I can tell you from personal experience that makes it a major pain to take off the horizontal stabilizer.

Rigging is easy, primarily due to the light weight and short wings. However, two things to be aware of. Somebody who is completely unfamiliar with an L-33 can get the main pins installed in such a way that they look like they are in and locked, but are not. On glass ships, the spar butt length is about the width of the fuselage, but on the L-33 the spar butt length is about half the width of the fuselage. That makes it difficult to hang on to it while sticking the spar butt into the hole. Best to use three people, two on root (one on the trailing edge, one on leading edge), and one on the tip. Or use one man rigging gear. Yes, I have rigged L-33s many time with only two people, but it was a challenge for me to handle the root by myself.

Flying X-C in the L-33 was fun, but it was annoying to watch the glass ships consistently out run me. Out climbing them was fun, though. Look on the bright side, your son's land outs will be closer to home. Make sure you get a good trailer.