I have been building speaker kits since I was in high school. I was kinda forced into this idea by getting burned really bad by a fly by night audio salesman. Since I was in woodshop already, I had everything that I needed for the task.
By a wide margin I can say that kit building is as good as anything that I could afford otherwise. Yes, you take the chance that you won't be satisfied with the build soundwise. Just like paying good money buying a speaker.
GR Research offers a sub kit that I built last year, and it is one of those experiences/outcomes that I will never regret. I prefer to build my own enclosures for the sake of quality, but the parts supplied by GR Research were the best that I had seen in some time.
I am not so naive to believe that things won't change with any company due to various reasons. I will be paying close attention to how things progress.