I rode the Levi's Gran Fondo on Saturday - it was a great, beautiful ride up in Sonoma county, with 7000+ bicyclists participating. It had a mass start, which was a new experience for me. It was kind of stressful being surrounded by bicyclists at all times, trying to figure out if I should be passing or pulling over to be passed. I think I enjoy riding by myself more where I can just go at my own pace.
But it was fun to have the roads closed off and have cops wave us through stop signs and traffic lights. And I definitely pushed myself harder than I do when I ride by myself - I used up everything I had in my final sprint to the finish. So I'm glad I did it, for sure. http://www.strava.com/activities/203371710
One other side note - I had my first flat in a while while riding. It happened towards the end of a climb and I was near the rest stop before I noticed it, so I just walked my bike in and found my tire was completely flat. I replaced the tube pretty quickly, but then had some more time to kill because they closed the road (bad accident where they had to helicopter a bicyclist out), so I started trying to patch the tube since I only had one spare, which I had just used. I put three patches on and was still finding holes in the old tube, before I gave up, and just went over to the mechanic's tent and bought a spare tube from them.
The funny thing is that the tube blew out completely like that on pavement - I don't recall hitting anything like a pothole that would have done that, so I'm not quite sure quite how it exploded so thoroughly. Later on, I did the dirt road option for 10 miles, and worried I'd have another blowout (which is why I really wanted another spare tube to be safe), but had no issues. Bikes are weird.