10.5 works fine, so the question is, why update?
I recall seeing some people complaining about some bugs with the 10.5 build (I think it was related to form controls but I am not sure), for them, updating was sort of necessary, also, 64 bit support (but losing XP support I think).
But I agree with you completely that if it does not bring anything worth it, staying at the same version is fine for now.