First of all, I think that the SixtyGig community doesn't need plugins to work.
Like WW already mentioned, there is no griefing etc. on this server and I am most certain that we as a group don't need chest protection and stuff like that.
Personally, I can go without fancy chat colors. I like the idea that everyone's on the same "rank" but I agree that it's probably a good idea to give weight to long-time members' opinions. On the website, which is where the important things are discussed, we still would have our colors though, so there wouldn't be much of a problem I don't think.
Okay, I would miss is the wilderness. In minecraft, I'm a "gatherer". I like to go mining and don't feel bad about it. With a wilderness that resets regularly, I never feel guilty of "stealing" someone's resources (I know, that one can always generate more terrain but it just doesn't feel the same to me). And as WW said, Multiverse is available for Spigot.
On the other side, the absence of a wilderness maybe is good for me. I could start focusing on building more instead of piling up my diamond blocks...
Everything considered, I'd enjoy pure vanilla. Yes, it certainly would force me to readjust in one way or another but it would be an opportunity that I would benefit from.
Maybe it's true what they say and less is more sometimes. :-)
Albert, mein Freund
ich wünscht es gäb nen Ort
es gäb nen Ort mit zwei Charlotten dort
ein jeder von uns nicht allein
und endlich wieder Freunde sein