On the topic of X-rated or not, can I offer the contrarian view that the longer the ride is, the more I appreciate X-rated. On 200s, check points with a friendly AUK volunteer and free/cheap food make for an easy day ride. But on everything past 600, I would rather sleep in a hotel room with a nice shower (I'm fast enough to get some sleeptime, slower riders may have different opinions). I still appreciate the volunteers at the controls, but I always feel I spend too much time there.
And I think audax will recover from this. I'm a solo rider mostly, but I find it comforting that I'm not the only doing some insane 600/1000/etc ride. The fact that there is some record of what I'm doing, or that there is someone at the finish, pushes me further than I would do on my own.