I love their design architecture, a full OS being bytecode based besides the kernel infrastructures since 1988, while we keep getting from those SV principles how WASM is going to change the world.
Naturally NGEN has the caveat of only being good enough for faster startup, and requiring strong binaries (aka signed dlls), which meant not everyone adopted it.
Windows 8.x adopted Bartok from Singularity, where applications would be precompiled on the store, and linked on device at instalation time.
Windows 10 moved full AOT compilation into the store when downloading into specific devices.
Note that full AOT on Android is only on versions 5 and 6, starting with version 7 onwards is a mix of interpretation, JIT and AOT, which is nonetheless quite cool.
Also there are several optimizations that are only possible after having PGO data, and that was lost on AOT at installation time.