I agree with the two RB trade for a better receiver idea. Muhammad's problem is the Bears' QB. Still... I think Jones will lose the job to Benson sooner rather than later.
For me the decision would be...
Should I stash Jones for next year (maybe playing somewhere else)
if not,
Is Muhammad's present value greater than Jones if he goes PT.
If you're not going to keep Jones or not likely to trade him in a package, I'd take Muhammad for current year production.