Gerry sounds terrible, but is it worse than Ed (which I recently watched)?:
This was actually so bad that it was hilarious (especially the baseball scenes).
I've never seen Ed, so I can't say for sure which is worse, but even if Gerry is technically better, it's still worse. It's an actual movie, made (ostensibly) for adults, not 'the guy from Friends plays baseball with a monkey,' which most people would know better than watching with any sort of expectations. Gerry tricks you, because you're thinking, "Matt Damon and the Affleck that's actually a decent actor in a movie with good cinematography and (supposedly) good dialogue by the same guy who did Good Will Hunting? This must be pretty good." Then you get hit in the face with a steaming turd.