In co-op it may be tolerable (I know that you've played the demo a ridiculous amount in co-op) but otherwise it just isn't that fun. The sequence we play in the demo is just one big hold-off of enemies. Just running around, collecting stuff, shooting enemies, rinse, repeat.
The atmosphere and objectives in Shanty Town (like protecting Sheva with the sniper rifle) are just more compelling. Though, I'm not big on the chainsaw fight either.
In fact, none of the chainsaw fights in this game, I bet, are going to be that great. In one of the previews I saw, they showed a fight with the chainsaw Majini in the warehouse, and that didn't look fun at all. Just that same run, turn around, shoot, turn around, run, turn around, shoot bullshit that I've been tired of for a while now.
But yeah, the main offender is Public Assembly. Just doesn't do anything for me. Even as an action sequence, it's merely "okay."