Just copied and pasted my response about the summer between MS1 and MS2. The MS2s would be the best people to talk to about this, but they're in their dedicated period right now so I can only give you an MS1's perspective right now.
As with any med school, yes, those questions crop up. Generally, you can tell faculty about what's working and what's not and they'll try to adjust things if they're able to. Some blocks and faculty are better than others. The curriculum and calendar are pretty set in stone though so huge changes are probably not gonna happen. You also fill out end of block surveys where you can mention what worked/what didn't, etc. I'm not sure what happens to the surveys after they're received by UW though.