I used to be a huge Ibanez wizard neck guy - had 6 of em at one time.
5 went south - they warped and wouldn't come back. I'm not as worried about it now - if I buy one used I check the neck out, and wood gets stronger as it gets older. I had most of my issues back in the early 90s, and the band I was in did several outdoors gigs.
I'm betting that neck was the one without the big 'skunk stripe' on the back, right? If you really dig these guitars, look for the AANJ/skunk stripe necks, they are quite a bit more stable. For the extra $, the Vai necks were stiffer IMHO - I never had to adjust the neck on my JemFP. I think it was quartersawn and the standard wizards flatsawn. Could be wrong though... I'm going by memory on the Jem. It was noticeably stiffer though.
Pete