I have to say that my first reaction to this idea was negative for the reasons given above; I see that the motives are good and in an ideal world, all feedback would be honest but there is the possibility that some members would abuse this facility to get at other members.
Also, sometimes with swaps things go wrong through no fault of the person involved - life gets in the way and I'd hate to see someone bad mouthed for not delivering when they had an as yet undisclosed valid reason for the tardiness. An apology could be issued of course but mud sticks as they say. :hunf:
If I were you, I wouldn't. :-)