Can't comment on Mayones, but the one issue I've had in many years of multiple Warwick ownership was a tuner that stripped its innards and promptly exploded without warning. Don't be put off by that. Particularly since I had a proper replacement delivered in 48 hours and installed in 10 minutes.
Generally rock-solid instruments, but with the advantage of easy-to-source spares and they're easy to work on.
Beware the barrel jack-sockets, they can work loose. The Just-a-nut II is fragile, and vastly inferior to both the I and III. And the old school recessed straplocks can supposedly cause the bodies to crack.
I've not experienced any of these, though.
The construction is very robust, but functional rather than elegant.
The necks are pretty stable.
Some of the pickup/EQ combinations are arguably a trifle bland sounding- but some designs (Dolphin, Infinity, Thumb) don't seem to suffer from this, in spite of using ostensibly the same parts as some other Warwicks. Maybe it's the wood choice and pickup placement.