We hit Roswell during their UFO Festival last summer on our way from San Antonio to Albuquerque. We didn't bring our 5er as we only had a few days to visit with DH's brother on the 4th of July and he had a room for us.
They had the main streets blocked off and we had to detour, but it was okay, since our motel was on the north side of town. We ate well at Cattle Baron Restaurant and got our T-shirts when we filled up with fuel, but otherwise didn't want to wait in line or try to find a parking place for the dually. On the return trip, festival was over, and we only stopped at McD's for breakfast and didn't have a problem parking. We spent more time at the West of the Pecos Museum in Pecos, TX than siteseeing in Roswell.
From their website: "This year the UFO Festival is scheduled for July 5-7, 2013. But plan to stay the whole week from June 28 through the Festival because Roswell has a lot going on that week."
The route was good from Fort Stockton to Albuquerque. Mostly 2 lanes, but then it changed to 4 and was smooth sailing.