From my experience there are goods and bads. *I'd say overall I've been impressed with the people I've worked with for custom work. *The neck I got done was by far the best playing/feeling guitar neck I've ever played. *It's based on the Jem10 neck. *However, this did not 'feel' like a Jem10 neck. *For obvious reasons such as a rosewood fingerboard but more in the playablity of the neck. *I feel the craftsmanship is by far higher quality than what I've played from an Ibanez guitar. *Now don't get me wrong - I certainly love the factory necks, but there's just something about the custom that's better. *Perhaps it's that ONE person built and spent lots of time on it rather than going down an assembly line where there's lots of people working on it.
On of the bads, as mentioned, is the time it takes to get a custom made. *Perpare to wait up to 6 months or more.
Bottom line is I'll never stop playing factory Ibanez guitars because I love them so, but I will turn to my custom when needed.
If you want more details on who I've dealt with feel free to e-mail me.