I've had my kit about a week. Thus far I'm very happy with it. Not sure what the issues were with the ab buttons as mine wasn't missing any. I came here first and did a LOT of reading. I went to just about every vendor site and asked tons of questions to the suppliers. I based my decision on the fact that I would have to be building my armor from a kit and NO kit is automatically approved by the 50st. It all comes down to the individual build. I think too many people have the misconception that you open a box, put on the armor and you're done. I've been through this with people in the R2D2 Astromech club and BB8 builders club. They think 3D printing is perfect and they shouldn't have to do any additional work. You have got to put for the effort. I think this kit will be just fine IF it's built right and the CRLs are followed.
I talked to several 501st full members and one of them order this same kit. Since he's built one in the past I'm waiting to hear his thoughts on it when he receives it but after spending hours talking to the guy I don't think he'd waste his money on junk armor and seems very knowledgeable.
As far as vendors go, David has been professional and answered any question I've had. And from what I've heard personally from others who have ordered from David, any issues with their kits (missing or damaged parts) he's made it right with them. Anyone who is curious about these kits is more than welcome to check out my build thread folder on my Facebook page. I'll leave that folder open to the public so anyone can view it. Any questions please feel free to ask.