Both looked nasty but Traven's arm definately looked in worse shape at UFC 34.
Travern dislocated his radius which is common and easily reducible. Sylvia fractured at least one of the bones. This will take plating and screws.
I would go with sylvia having the worse for wear
6-8 weeks is nonsense. I say 6 months before he is even able to train full blast. Vae Victis. But best wishes for Sylvia to make a strong recovery.
Tim's looked worse because you see the actual snap. I've seen a lot of double jointed guys who take armbars nearly to the point that Traven did and they didn't tap. Speaking of not tapping, remember when Joel Gerson armbarred Rumina Sato and had it set and pulled for about 20 seconds??? Man. Sato didn't even tap and the ref had to come in (Shooto rules). That was crazy...