A few comments on the 2/27 X (stable) build, as I can't find any other place to post about it:
There is something wrong with the debug version of this build. When an error comes up, it goes into an unending cycle of minimizing and maximizing the game very rapidly, so fast that I can't close it in the task manager, and effectively crashes my computer. I'm actually getting this whenever the game displays a briefing stage with lines in it, but I can't tell whether it's specific to that or if it's a general, error message popup issue. Not sure if this is a bug in the code or just something with this particular build. The release build has no problems.
The crashes during mission loading seem to be more frequent in this build, although all the builds have done it for a while now. Although I'm not sure if this will help any, I got the debug logs from a crash and a successful load for the same mission. The last entry in the crashed log file is "ANI Lamprey_Impact.ani with size 80x80 (37.5% wasted)" and the next entry in the other log is "ANI 2_lock1.ani with size 53x53 (17.2% wasted)," so it's apparently crashing on that. There are three points in the loading sequence where I've repeatedly seen the crashes though, so this may not necessarily mean anything. The release and debug builds both crash the same way, with the generic windows error.
There are also some performance problems in this build. I'm noticing the framerate drop sharply several times near the beginning of many missions, although I haven't been able to determine exactly what causes it. It was not an issue in the 1/24 X build I was using earlier though.
Finally, I think there is some odd behavior with certain large ships blowing up, where the debris seems to contain two copies of some parts of the ship. I don't remember seeing it before, but want to confirm it before putting it on Mantis.