I've been to The G4 Experience in 2015 with Joe Satriani, and Vai Academy back in January this year.
Both are also organized by Dream Catcher Events. They're a pretty good crew and do a good job.
People bring guitars. I brought 2 both times, plus my Axe Fx II and one Xitone to play around on in the hotel room during downtime. No point in bringing a guitar to the master class sessions, though.
They were run very differently, but both were enjoyable.
Joe's camp was a much more "even" split between Joe, Animals as Leaders and The Aristocrats (the 3 main attractions, there were others, too).
Steve's camp was much more focused on Steve, with the other artists (Steve Morse, Yngwie and Annie Clark) joining him and also having shorter sessions by themselves.
At Joe's camp, there was an hour-ish long concert every night, followed by "camper" jam sessions.
At Steve's, he would play 2-3 songs at night and then one song with one of the guest artists. Then he and his band jammed with the campers individually (there was a schedule, everyone got the opportunity). There were also camper jams.
During Steve's camp, there was much less downtime. I was engaged pretty much from 8am until at least 9pm every day.
It isn't cheap, but I really enjoyed both events.
I never got into DT, so I'm not that familiar with Petrucci (plus I'm in CA) so I don't think I would attend unless the guest artists were super appealing.
If you can afford it and like the people that are going to be there, you should do it. I was amazed at all the people from all over the place that came - especially at Vai Academy. Guitarists from all over the world.
Also got to jam with Larry Mitchell, which was great fun!