Well here are the changes i have noticed in 23052:
1. The top bar now can be accessed from any screen, and has colored, beautiful icons by default
2. The windows default spelling suggestions now dont come in your way when you are typing a message or email. Previously the suggesstions popup was so large and it use to cover the middle portion of screen even when you have typed text there. now the suggestions popup moved to the upper portion of screen in such situations. This is a great improvement.
3. The radio buttons are back to the ugly ones in some areas like Volume Control, Advanced Network etc. But at some places its normal, skinned one like in Settings>Input. I dont like this.
4. Checkboxes are fine everywhere but the Home Screen settings. The screen which lets you select today plugins is looking ugly with the transparency mask (the magenta color around checkboxes) is showing up, eh!
5. The icon problem in apps that use listview control like dotfred;s task manager, pimbackup etc is gone.
6. Dialer is working perfectly well even with my custom skin.
Overall, its a great build, with only a few glitches. 2-3 builds more, and it will be fine. Specially the alignment of controls on screen is getting better.
21857 is having the same AKU no and as expected there is no change to the feature list, although its working faster as ever. Great build overall.