i can't go into details, but in contrary to what somebody else posted here, GC is worse than manual memory management. of course you do not compare a bad implementation of memory management with a good GC. you compare a good memory management with a good GC. the lack of control yields a damn lot of situations where a memory limit will cause big issues with any kind of GC.
GC are in general only for usecase where you actually have either a lot of memory or time enough.... or your customers/clients can live with the drawbacks.