I don't see how you lose 3 prizes to "set up" Eggs. That would mean losing 3 Celebi, which means you're having terrible luck to begin with. Meanwhile, you are stopping their setup with CC/BF/Crystal Beach.
OK, so 90hp isn't much, but I don't see flipping tails on everything, ESPECIALLY if they're set up, and I don't see 90hp losing to many OHKO.
About Ambipom, it does have 2 uses. It works well with the Team Galactic, and it spreads weakness. It also adds Colorless type vs dragons and such.