I have also heard all the negative spill on Jim and all I can say is as far as I'm concerned he's a good dude. He is a talented air personality who "gets it". The problem with talent like that is sometimes they are surrounded by or work for people who don't "get it". Does he raise hell when things aren't right, does he put his opinion in at times when it goes against the grain? Yep, but I don't think it was ever in any form in an effort to derail the product, only an attempt to make things better. Unfortunately, some don't take kindly to being challenged and this can rub things the wrong way. That may sound like an excuse but, again, I think he has always been concerned only about the product, and I'd have a hard time finding wrong in that.
Beyond that, he is a human being just like you and I, capable of errors in judgement or actions at times. Until you are ready to prove your own personal perfection, why such negativity?[EDIT]
I have recommended him a few times to anyone who's asked, and would again.
[EDIT-inflammatory]