11.52 was beta and is no longer offered. Best to steer clear of test builds unless you're experimenting.
Ran tests on a twenty-minute 1180x664 mp4 @default H264 settings, 46fps. 32-bit. (11.21 wasn't available - may have been beta.)
11.22 :52 average 54% GPU
11:38 :56 with 50% GPU
11:52 :56 with 50% GPU
Re-exporting may yield slightly different results.
Devs constantly strive for performance improvements but there may be tradeoffs, and with a robust upgrade cycle glitches do creep in. When confirmed they are quickly dealt with.
Of course, hardware can be a factor. No two PCs are identical. and your video adapter may not perform the same as mine with a specific release.
