While we fixed the perf regression issue in B3, we still had aircraft mouse-rect and animated part issues left over and found a photo-scenery corruption issue. In both default and 3rd party aircraft. Thus we felt we needed confirmation on those fixes.
So we posted B4 at about 5:35pm PDT today. Jon Patch was first in at 5:37 to start downloading, Now we wait to hear that we fixed these issues.
This should not significantly delay the release of SP1, because we expect to take only 1-2 more builds before having an RC for RTW. Then we final test, then we ship. We will ship SP1 in the month of May.
We want to get it right wrt performance and not introducing any regressions.