I think Barton deserves a chance on his form this season and last to a certain extent, the obvious problem being his temperament. Id be suprised if he learns to control it overnight, the Mendes incident the other day being a prime example of that- could we trust him to keep his cool in an important match? Probably not.
I dont think he is as good as Lampard, Stevie, or Hargreaves no, but maybe he might fit into the team better than Lampard or Gerrard. I dont think you can play both of them, and maybe Barton is the answer (although god knows what the question is:D, who is the most likely to end up in jail in the next 6 months lol)