It's not about the size of the hitboxes, but more about the feeling. I get between 48/55 acc on Silent most of the time (with mp40/thompson), same counts for Jaymod. But with Silent I have the feeling that I didn't shoot well. Jaymod feels more fluent when you switch really fast from target to target, or make a 180, when I do this with Silent I get the feeling that I just shoot right through them.
I also had a test server running for a while with silent and some of the members said that they feel somekind of delay compared to Jaymod.
@Dragon: Could you tell me the differences between administrating silent and jaymod? From my experience installing silent was way easier than jaymod, but so far I don't see any reason to switch to silent, although they have really cool features like: guidsytem and the mapvote mode, but I can live without that.