I have a 28 point build sorc at level 20, had her since I've started playing, mostly waiting for a PRE to come along.
From what I've been reading... erm... I don't know if it was worth the wait. However I don't play on lama so I have no first hand experience. While it has read as kinda the worst PRE I've seen (none of the others come with such a big downside for such a little bonus) since I haven't played it I can't say for sure myself.
For the longest time I've been debating TRing my sorc in to a wizard, mostly so I could have DCs worth something since nuking frankly doesn't work well in epics. Also, vampire looks like a lot of fun.
Anyway, since I can't make up my mind I'll just ask you lama players: Should I GR my sorc to be a savant or TR in to a wizard?