The MySpace situation is very fractured, IMO, and sometimes those dividing lines run along age groups. For example, in the case of Hyde Schools, you have over 40 years worth of former students who are often, as Hyde School seems to ensure, still highly opinionated as to the appropriate take on the whole experiment. That ends up with former classmates clinging to their own "crowd," namely the folks who experienced pretty much the exact same conditions that they did, at least as far as certain non-subjective variables are concerned (staff, admins, lingo, etc.). That, of course, doesn't even touch upon the pro- vs. con- issue.
From what I can tell, there are a few Hyde MySpace groups, but often they are short-lived, and infrequently posted in. They generally tend to attract the younger ex-students.
There is also the issue of certain hell-holes being successful at having certain MySpace groups gutted of unflattering content...which certainly puts a chill into survivor discourse.
Personally, I think a larger MySpace Group with potential sub-groups (much like the structure of fornits) would be the most effective strategy in reaching and/or being palatable for the largest number of people... But I am hardly the expert, lol!