Honestly, I don't need Bethesda to apologize or give an explanation about why they didn't make this in the official release. This mod improves performance, ok. How many people tested it? No crashes so far? If so, then what I'd really like to know is if Bethesda is willing to add this mod to an official patch. If not, I don't mind using the mod, but I'll wait until the official mod directory is supported under Steam Workshop.
There are are at least 30 testimonials in these threads:
http://www.gamesas.com/topic/1321657-tesv-acceleration-layer-offers-cpu-optimization-massive-possible-performance-increases-now-in-skse-plugin-format/
and
http://www.gamesas.com/topic/1321575-rel-tesv-acceleration-layer/ (original)
Anywhere from 5-25 average FPS gain, mostly tested in cities, especially the two biggest FPS eaters: Markath and Riverwood (maybe it's all that water?)
Also, checking with Xbox360 dev guys, the function inlining portion may be applicable (if Bethesda so chooses).