JustArchi, developer on XDA Developers has revealed a long series of optimization for tweaks Android. The idea here is that the original compiler settings since Cupcake has not changed. On the other hand, the target platform has changed drastically with large screens, multi core CPUs and GBs for RAM.
The article lay the foundation for the optimization fixes. It sounds fairly reasonable proposal.
So, what is it about? As we know, Android contains a bunch of low-level C/C++ code, which is compiled and acts as a backend for our java's frontend and android apps. Unfortunately, Google didn't put their best at focusing on optimization, so as a result we're using the same old flags set back in 2006 for Android Donut or anything which existed back then. As you guess, in 2006 we didn't have as powerful devices as now, we had to sacrifice performance for smaller code size, to fit to our little devices and run well on very low amount of memory. However, this is no longer a case, and by using newest compilers such as GCC 4.8 and properly setting flags, we can achieve something, which I call "Android in 2014".
Update 10 Jun 14
Flashed a new build on 9 Jun. Performance, the jury is still out. The usual smoothness in the interface is still there. I noticed that the memory management has improved/fixed. April and May builds have strange behaviour. All the apps works except for Google Camera. Yet to find the root cause.