Depends. The only thing that is a bit of an annoyance is that it can blow out oil though the breather. Usually sorted by putting in a bit less or using the Filler cap/breather. See how it goes. We use Dexron oil in the gearbox as it's a Gas Gas style clutch and it seems to like the same oil. The Frame bolts like the Beta can rattle loose so loctite them in. We have a thicker bash plate but my Son likes rocks and if he misses the standard one is a bit "thin". Some have a head insert to lower the compression but what we have works fine. After that it's down to personal preference and how you ride. Just post any queries and we will see if anybody has come across the problem. Most riders who have tried My Son's bike love the ride and the way it handles.
Mods to His bike are, Kehin Carb, Boysen reeds, Ohlins shock with heavier than standard spring, Costa Sump Guard, Big AJP clutch reservoir, Added clearance on the Two "fingers" in the linkage, (it "clicked" on rebound). Only thing that would stop him from buying the Racing? If he tries the TRS or Vertigo with EFI and likes them. He does not think the current crop of bikes are as good at the JGAS.