CurrentSea-
Saybrook can be ok, just depends on where you are. If you stayed at Between the Bridges or Ragged Rock, it could get a tad rough in the wrong conditions. I know a few people who stay there and havent sadi anything negative about it. You could try the Brewer yard there. I think its called Ferry Point. It is after the 95 bridge so it should be calmer.
As far as fireworks are on the river, not sure about anything except Middletown, which is good, and Portland, which are awesome. Im not saying that because I live there. They are some of the best in the state. The problem is that coming by water kinda sucks. No real place to stay but on the hook.
We were in Sag last year, and they were great. The yachts made a great back round for them. Lots of parties on the big boys, so there was plenty going on. I think we will end up back in Sag for the fourth and then to Block from there. Cant wait till Memorial Day though. We have around 12 boats from our marina that all stay at Mitchell Park. I love that marina.