If you read the Stako thread in AC&Q there's some more in depth explanations to do with why the Stako bottles may leak some air (air which isn't actually leaking from the core of the tank, but below the outer layer of the tank) and is to be expected when filling from empty due to the nature of how they're manufactured.
The company has been producing tanks for 40 years now, and the paintball specific ones have been available for a couple of years. So I doubt they've rushed them and I would be extremely surprised if there was an inherit flaw with the tanks due to 'lack of research'. Still, I look forward to hearing the official word on the current situation. (Although at this point, I probably would continue to use my Stako if I were allowed).
As for the mini - 2 main problems I believe.
1. Bad batch of resistors with some of the original 1.1 boards. Not exactly lack of research, just bad quality control. Still, a big screw up.
2. The poppet problem. My current understanding is that again it has only affected some minis. This could probably fall under the lack of research/testing category. I'm not sure if it was a problem that could have been spotted and/or rectified in the design stage. But assuming it wasn't obvious then, and it fell to actual product testing, how much in field testing can you expect before a product release? I heard they were being shot for quite a while disguised as ions for testing - and then it was about 4 months or so after thousands had been sold that any kind of blowback problem due to the poppit was widely known. All things considered, I think they did alright if it wasn't for the f*ck up with the boards (and resulting lack of availability at release).