It offers several improvements, i.e. fixes the keyboard sound lagging, wifi driver hanging and popping sound when changing tracks (which was actually fixed in 8107), but be aware, it will prevent interop unlock in the future! Make sure you're still unlocked on Tango before upgrading, otherwise you'll have to restore from a backup.
I know this because I neglected to make one and am now SOL without interop.
Do we know for certain whether it's the Tango update or the Samsung update that kills the interop unlock?
It would help those doing the force update on Zune if they knew which as they could halt the update before the relevant stage, and apply the prevent relock XAP before the final stages.