XenonHD is directly based of AOSP, but is peppered with many additional features. There are already noticeable differences once you start your device after installing the ROM: the notification bar is semi-transparent and the look of the soft buttons is suspiciously reminiscent of Motoblur.
Once your device is unlocked, the ROM seems to be as per any normal pure Android device. However, the difference is quickly noticeable once you switch between home screens. The XenonHD launcher, which replaces the default launcher from pure Android, is blazingly fast. But while this is interesting in itself, I was mainly concerned about the ROM settings that can be found in the Global Android Settings.
Smartphone or Tablet?
In the "ROM Settings" you will find more customization options. Here, you can not only change the UI mode (which optimizes the ROM for either using on a smartphone, a tablet, or a phablet). This is similar to other ROMS, such as ParanoidAndroid or AOKP.
But that's not all, because Xenon HD also offers many more interface options that allow you to change the appearance of the system. Whether you're looking to change the transparency settings or visual options for the lock screen, it's simple thanks to the clearly structured menus that are ridiculously easy to find. There is even the popular PIE Control from ParanoidAndroid available to be used.
In the Performance Options, you can also change the clock speeds of the device, change the voltage of your CPU, and also manage your memory manually. This can boost the performance of your device quite a bit, however, it's important note that users should beware when customizing these settings as you can cause some pretty hefty damage to your device should you mess around these without knowing what you're doing.
XenonHD has given my Galaxy Nexus a real boost in speed and given me the option to completely customize the system to my needs and wants. The software may seem a bit overloaded, but thanks to a well-structured settings system, you will find what you need without much searching. Definitely check out this custom ROM, as I doubt you'll regret the decision to try it out.
XenonHD is available for a variety of devices. Find out more information on what's compatible and how to download it on XenonHD's official website.