I hate to say it, but for me, the harder the better. I am trying to decide between Paris Mountain or Langley Pond. Langley will be longer, but this sounds much harder. Unless I can find an HIM in June or July, this will be my only "hard" race before IMKY.
I can't do it because the timing with other races doesn't work out for me. But it looks interesting.
Langley is a really nice race, in my opinion. The terrain is similar to IMKY, by the way -- rolling bike (not as steep as a couple of the climbs at IMKY, but similar overall) and flat run.