Love my Mezz cues (Cp-21/Ace 2180) - and that's coming from someone that not too long ago believed definitively that buying a cue specific for pool was for dummies... and that I'd always use a house cue. My attitude has shifted significantly in the months since I have switched to playing pool more often over snooker.
I was put-off mostly by the aggressive consumerist marketing... that and all the nonsense my friend would chat about "tech"
Eventually I caved due to the fact my friend sold me a Cp21 for cheap cheap (I have had the same snooker cue for 15+ years, and bought two same spec customs to replace it when it was stolen from me - the player learns the cue, doesn't buy themself a better game was my logic, and what I had been taught). I later bought an Ace, second hand, as a back up butt. Also a well constructed and well balanced piece of wood.
Hybrid pro, Expro, ILC monster pro (custom made by ILC) - all of these shafts play perfectly, and are well constructed, fitting the joint flawlessly. Mezz does everything you need it to. A custom cue may or may not feel right... But it will certainly be aesthetically more suited to your taste, which is the main reasoning for buying, not some special manufacturing process, or magic cue that will make you play better.
A lot of the joints used by custom manufacturers are pretty universal, so I wouldn't worry about things not being replaceable. I recently purchased a beautiful Larry Vigas that I literally fell in love with from an aesthetic perspective. The finish and texture of the wood is insanely beautiful. It just so happened that when I tested it, it felt 'right' with both the shafts included (also having a joint that allowed for easy access to other shafts in the future).
Is it better than my Mezz? no. Is it more exclusive? Being 1 of 1, custom. Yes. Enjoy that feeling of ownership, and hope it adds the necessary placebo to your game
I'd say, if you can afford it, go for it. But the quality of Mezz, is actually not to be scoffed at.