I do like Jon Favreau too even if IM2 was a mess, but he probably works better for solo movies. Joss is amazing with ensembles - and female characters.
I guess I just have a lot of goodwill left after IM, which I liked more than Cap and Thor combined. I don't feel like it's fair to blame him entirely for IM2 since it seemed like there was quite a bit of studio interference. And I think, he might not work well with ensembles, but that doesn't mean he can't do solo movies.