Having a company in the US that you can get support from is definitely worth something!
Having a printer that a lot of people use is nice too, as you don’t have to try to design your own upgrades, other people already have.
The monoprice makerselect are like that, @notfastenuf has one, maybe he can chime in with his experience.
I built mine from a pile of parts “kit” with dubious instructions, it took around 14 hours and would have taken a good bit longer had cnc routers not been my previous career path.
The flip side is that if you do build it yourself, you know exactly how it goes together, giving you a head start if something fails.
It’s not hugely dissimilar to building a quad really, there are just a lot more parts. Same attention to little details applies.