I've never commissioned a custom build myself, but I have owned a couple of second hand ones, an Overwater Progress Deluxe 5 and a Kinal MK-5, both of them were utterly stunning in every way. So why did I sell them? Because I'm an idiot.
I guess in my case it's just GAS that get's me every time, and the trouble is, I'm skint, so if I spot a bass I [i]must have[/i], I have to trade one out in order to get it.
Frankly the ESP Horizon 5 I'm currently using as my main bass is [i]almost[/i] as good as either of the aforementioned, so I'm pretty happy, but for how long??