Kinda. The most unreliable part is the transmission. Pushing 400 ft lbs of AWD power through a 700r4 wasnt a great idea. There is just not enough strength in a 700 for that kind of abuse.
Kept stock they are very reliable. When people start “modding” them without proper knowledge thats when trouble starts. I wouldnt touch a SyTy that had had work done to it without a ton of documentation.
IMO they become “unreliable” when they fall into uninformed hands.