Our max limit depends on what the parks offer. Many times as we start to get more ticket sales, the parks may add on more stuff to accommodate more people. This is why it's so important for us to front-load ticket sales as much as possible as we have a better chance of them giving us additions early on than later. So we don't really know the limit for sure until tickets go on sale and we see how sales are doing.
That being said, events with more than 200 people start to push the boundaries of "cool stuff" you can do with a group that size, so when we reach that number, we look to the parks to open options for us. We once had over 600 at West Coast Bash at SFMM and IMO that was just way too many. After that year we started significantly limiting ticket sales so we wouldn't have that big of a group again.
Quality > Quantity is what our events are about.
Thanks for the insight. . As a newbie, I fully respect that. If I miss it this year I will try next year. Still may plan a MM visit in the fall, though, because I don't know if I can wait so long to ride TC.