This is the first, "Stolen Pig Rally," so I have no experience. I have met the sponsor, the "Real McCoy," and spoken with his wife on the phone; really nice people; I wouldn't hesitate to recommend their event to anyone. I'd think the KLR650 would be fully appropriate for the routes; public access roads and trails.
Laurel Fork . . . while I've never attended, comments suggest to me the event's closer to the, "drunk-fest" category mentioned earlier. Bunch of wild-and-wooly young gentlemen with shenanigans on their mind. The routes they choose might favor a more dirt-bikey ride than a KLR650. A rowdy bunch, and a raucous affair, in my estimation (not that there's anything wrong with that!).
Romney Cycles Camp And Ride: Absolutely suitable for a KLR650. MANY diverse routes (and riders) to choose from; from all-pavement courses including Freeways to Nowhere, to gnarly single-track and water crossings . . . you get to choose the type of ride you want. Also, first-rate operation and management; and . . . FREE.
Horizons Unlimited Travelers Meeting: You might want to Google this one; excellent campsite (4-H Club Camp), presentations, training, ride-outs . . . all you always wanted to know, but were afraid to ask, about adventure riding. Costs some money; on-site meals good, but a little pricey in my estimation; long ride to alternative dining opportunities. Fully KLR650-friendly.
I've attended a Horizons Unlimited meeting and a couple of Romney Cycles Camp And Ride events. I'd recommend either to my sister (if I HAD a sister!). I think the Stolen Pig Rally would be civil, also. Laurel Fork? Noisy fun with the wild-and-crazy set, I'd expect.
As to Go Race: The current cast of characters there appear quite professional and civil, in my experience. I'd imagine they would share valid local riding information upon request.