That sounds absolutely wonderful! Those are my two favorite mansions, too. We did The Breakers this time, and tried to get into Rosecliff but they closed early for a wedding (must be nice!!!). One of my friends had never been to any of them before, so she was over the moon.
The jazz fest is at Fort Adams, which I see on the map juts out into Brenton Cove. And Brenton Point is to the southwest of that. I'll definitely suggest the scenic Ocean Drive area to my friends next time.
The nightlife was hopping this weekend, too. We ate dinners at about 7pm and the restaurants were quiet when we walked in, but by the time we were done eating we were yelling to each other across the table because it was so loud. It made me appreciate that our hotel was set back from the road and blocked by buildings so we couldn't hear the noise coming from Thames Street.
We had one celebrity sighting...Jay Leno came into The Red Parrot while we were having dinner. I can't stand him though, so I wasn't impressed.

ETA: He was probably staying at the Gurney Resort.