Cyberstretch, it is hard to give an answer. I am a developer, though not for CL. I would assume that all but one of your list would be considered critical at some point. For instance, rendering issues would depend on what the issues were. Didn't render at all? Critical. Render being slow? Not critical. The one I have a problem with is compatability to "usual software/drivers/hardware". And that is because no one can say what is usual. It could be a problem only in certain combinations. Maybe any of the three by itself would cause no problem at all, but two or three together do. There is not enough resources for any company, including Micosoft, to test every possible combination. During an Alpha Test one tests it on bare machines, at least that has been the practice my company employs. Then we go to a Closed Beta Test, where the employees run the software on machines that have other software installed. Then during an open Beta Test, meaning outsiders to the company, you start to see problems with compatibility with other drivers/software/hardware that wasn't caught during the closed Beta-Test. Hopefully you stamp out those problems before releasing. Even with doing this, there are still going to be issues that need to be addressed since all of the Beta-Testers still wouldn't have tested every combination. I do not know how CL handles beta-tests. I suspect it is similar.