Not to generalize, but the May show always seems to be the leftovers -- which can be good if some of the leftovers are what you are looking for, or if a breeder has head-started some yearlings. Even still, I've noticed vendors don't deal as much in May -- maybe because they don't have the stock they will soon have in Sept. (i.e lots of babies).
Yet, on the Saturday of the show, you can still make a day out of it:
(1) Go to the show from 9am-12pm
(2) Attend the cannabis rally at the State Capitol from 12-4pm
(3) Go to the beer festival at Moore Square from 4-8pm
(4) Go home, go out, or pass out from 8-?
The following show always impresses (b/c Jeff Mohr will be there :sidestep

I may have too many leftovers this year, so I may vend at that show if I find someone to split a table with.
Either way, a day in NC is better than a day anywhere else, and while the May show may not be as good as the Aug/Sept show, it's still better than a lot of other shows (see Richmond).