I'm really not sure what is wrong with McGahee. He can go through a streak of five games completely healthy and not get 100 yards but can come out against us and get 150 while playing on one leg. I would give our third rounder for McGahee at this point and nothing higher.
If a runningback has not proven out enough for his current team to try to ride him then he's not worth a first round pick in trade. The Saints traded Ricky Williams after they drafted Deuce McAllister and had two of those guys around. That's why they got the Dolphins to pony up firsts. They were trading a great back because they had two of them. And the Dolphins collapsed shortly thereafter, just like the Vikings did in the early 90's after trading for Herschel Walker.
Key words "he always tears US up". I'd rather get run on for 200 yards in a game twice a year then part with what could be a perrenial starter or more on this team for years to come.