Belt driven survives a crash and shaft gears don't. I have had bad luck with belts, so I prefer my shaft driven helis. I had a belt snap in flight and another one got shredded. I don't like feeding the belt through the boom and trying to get the belt tension just right. It is easier for me to get a shaft through the boom and set the gear mesh in a 1/4 of the time than I can with a belt. A beginner would probably be better off with a belt until they stop crashing as much, then go over to shaft drives if they want. You also don't have to worry about ESD and the temp affecting a shaft drive like you would on a belt. Either way helis fly great with a belt or a shaft.

Nick