Keeper League - P. Thomas in the 6th or Favre in the 12th??

Pierre has looked good in preseason, but I just worry about how much time he will be splitting.

He's projected to go 3rd or 4th round and I can keep him in the 6th round.

OR.....

Favre....what can you say, will he be like last year?.. or get hurt, throw 20 picks, etc......he's a steal in the 12th round, but solid running backs are hard to come by and a lot of the good ones are being kept.

This is driving me crazy

Please give opinions and reasons...Thanks in advance.