I have built plenty of rigs... COB, QB, strips but can promise you that the Chinese have really made some huge strides the past couple years and are making quality lights.
I wound up buying a fc series mars lamp for basically the same price I would have been able to put it together myself, and the quality is better than my strip build for what that's worth. The design is cool where the driver can be outside of the tent which can be nice also.
I remember buying a mars blurple like 10 years ago and swore I wouldn't ever buy another mars but the testing that I've seen on it was super impressive. There are ZERO dark spots in my 3x3 and only pulling 300w from the plug.
I know it's not answering your question but just thought I'd throw out what I found when I was planning on building a lamp last year. After that experience I also bought a "hyphotonflux" to check out and it has also been a very well made lamp. It has a slightly "warmer" light but haven't really noticed much of a difference flowering with both