I really enjoy shooting mine. S&B ammo is actually milder than what these pistols were originally designed for and is reloadable. I upgraded to a heavier recoil spring anyway. I haven't tried the FNM ammunition yet. It is supposed to be a little hotter than S&B but still within spec for a Tokarev, which is not as strong of a design. Makarov.com has a lot of information and carries a lot of new production and new old stock parts for very reasonable prices. About the only major safety concern is the decocker. DO NOT use the decocker on a loaded chamber without testing it for safety first. I would recommend not using it on a loaded chamber at all. The firing pins are cast steel and will break if dry-fired. Makarov.com sells new ones, as well as snap caps. I also had one of the locking rollers break, which tied up the gun. A set of new machined steel ones got me back in action again. With the new rollers and the heavier recoil spring my groups also shrank from 2 1/2" to 1 1/2" at 25 yards. This is the only problem I have had with my current pistol in almost 1K rounds. The one I had before had no issues at all and I really regretted selling it (hence the new one).
If your son is not very seasoned with centerfire handguns, it may be a little intimidating. The grip is fairly thin but rather long from front to rear and can be very uncomfortable for people with smaller hands. Recoil is not particularly heavy but muzzle blast is ferocious. Ejection is also very vigorous, throwing empties around 30 feet. I learned the hard way that this is not the best pistol to shoot on an indoor range. The empties bounced off the side of the stall and proceeded to hit me in the head. Hot flying brass with a fair amount of force hitting you in the side of the head is not conducive to accuracy!
Use the pencil test to check the decocker. First, remove the magazine and clear the chamber. Then double check the chamber. Point the pistol up and insert a pencil from the muzzle. You may have to try several to find a pencil that will fit freely down the bore. Retract the slide enough to see that the pencil is all the way through the barrel. (I know I am beating the chamber check to death but better safe than sorry.) Ease the slide fully forward and with the muzzle pointing up, pull the trigger. The pencil should jump and if the fit in the bore is fairly loose it will probably clear the muzzle. Reinsert the pencil, cock the hammer, and point the muzzle up again. Push the safety all the way up (past the SAFE position) and the hammer should drop. Observe the pencil while doing this. The pencil should not move. Repeat this test several times. If the pencil moves at all then there is enough wear in the mechanism to possibly cause a cartridge to fire if there is one in the chamber. If this is the case, you can either replace the sear or just treat the pistol as if it does not have a decocker, a la 1911. If the dealer you are buying from will allow it, test each one in stock until you find one that will pass this test. Then don't trust it anyway, because you can't predict when it will wear enough to become a problem.
I know it sounds like I don't like this pistol, but I really do. I'm even thinking of some custom work like replacing the military sights with some good ones that you can actually see. This is a gunsmithing/machining project and could wind up costing me more than I paid for the gun. Yes, I do like it that much.