Ubuntu 12.04 is currently in its beta and updates are rolling everyday to remove existing bugs and polish the system for the final release on April 26th. However, today I received almost 100 updates which is huge considering I update my system every few hours (call me paranoid). Notables updates have been made to Compiz and Unity. Most of the updates however are performance improvements rather than visual tweaks. Still, I will try to list them all to the best of my knowledge.
A small visual tweak can be seen when hovering above the lenses shown in the dash as can be seen in the screenshots below. The update brings a small arrow indicating the lens currently shown.
And that's pretty much the only visual tweak. But rest assured, there are several significant performance improvements with this update.
There were many users who complained about the delay in the appearance of the Alt-Tab and felt it made it feel sluggish and slow. This has been addressed in this update. The delay has been decreased from 150ms to 75ms making the Alt-Tab appears almost instantaneously.
One of the Compiz updates include a bug fix which reduces the compiz CPU usage by an astounding 42 percent. You can read more about this update here. Compiz is something that runs all the time when your computer is running with Unity. Hence this is definitely a major performance fix worth looking forward to in Ubuntu Precise.
Lenses are now lazy loaded instead of loading them all at start. This means that the lenses will be loaded only when you first use them. This will reduce the overhead at startup and will mean that your desktop is ready quicker than before.
There are other numerous bug fixes for Compiz. This update brought over 100 bug fixes for Compiz with more than 15-25 of them being Critical and 20-30 being High. Unity 5.6 has been released which brought a lot of bug fixes to HUD. Previously HUD interfered with Alt+F4 and other similar keyboard shortcuts. This has all been resolved now.*There has also been some keyboard shortcut changes in the dash. Pressing Tab switches between categories in a lens. Ctrl+Tab and Ctrl+Shift+Tab is now used to switch between lenses. This is similar to switching tabs in Firefox and Thunderbird.
These updates are certainly encouraging and improves the user experience of Ubuntu as a whole. However there are still more coming up soon. Updates to Multi-monitor experience is something everyone are eagerly awaiting. Mark Shuttleworth did mention that " we are scrambling to fix some of the multi-monitor issues faced by issues". So this is definitely their high priority now and will definitely see release soon.