Neca does have some QC issues but the price/quality ratio is the best I've seen out of any company. Not only that, their QC has been improving and their most recent figures are just great. I have about 20 Neca alien and predator figures and only one ever broke after a massive shelf dive. As of now, their figures have amazing sculpts, great paintjobs, better quality and articulation and a great price. Another giant plus for me, they have the greatest diversity of characters I've seen. From comics to movies to games.
Play Arts Kai has good quality, the articulation on their figures is only sometimes better than Neca's but that's it. IMO the sculpt on the Spitter and Lurker is not to my liking, especially the face, and the rest of the figure is just as good as Neca's. Neca had some really disturbing QC issues in the past, but I haven't heard recently anyone complain about a figure falling apart on it's own or out of the box. If that still happens from time to time, it's a lot less frequent and I hope that their customer service fixes that.
Play Arts Kai have great figures. But they're not worth their price IMO. If Neca continues to improve its standards, I wont have any complaints. Great price, great articulation, great sculpt and so much to choose from. I'd rather have 20 Neca alien and predator figs than 1 or 2 Hot Toys ones or a few Play Arts Kai, just as a personal preference.
As a collector, I appreciate the diversity and and affordability Neca provides. I know its not to everyone's liking and I'm not blind to Neca's faults. I just like being able to army build my xenos over the years with a modest income and choose from a plethora of different characters in their alien and predator lines.
Just look at the Alien in the Hadley's Hope two pack. It's a domed warrior and Neca's best alien to date.