For me, the humor mostly fails.
And where he does play things straight, there's usually either very little argumentation, or it's mind-blowingly fallacious.
Overall, I think that Jimquisition is far less bad than it was when it arrived at The Escapist, but I still don't see much worthwhile about it. The comment threads for his videos are also usually uninteresting, since it's mostly just part, "haha, I love Jim, so funny to see all these butthurt people," and part, "argh this is terrible, the other series' at the site are far better."