Via [url=http://blog.counter-strike.net/index.php/2016/07/15283/]the CS:GO blog[/url]:

[quote=Valve][UI]
– Radar is no longer hidden when win panel comes up.
– Shipping changes to how some UI elements are implemented in preparation for a move to Panorama UI. This should have no noticeable change in UI functionality, but is the first step in moving to the new system.
— Please report any UI regressions to [email]csgoteamfeedback@valvesoftware.com[/email] and include #UIFeedback in the subject heading.
[SOUNDS]
– Increased fidelity of firing sounds for P90, MP7 and MP9
– Added unique reload and draw sounds for P90, MP7 and MP9
– Slightly reduced volume of firing for recently changed weapon sounds
– Made headphones the default sound option instead of two-speaker. (If playing with headphones or sound cards with virtual 5.1/7.1 enabled, make sure 5.1 is selected in the CSGO audio settings menu instead.)
[NETWORKING]
– Networked viewangle precision to other players is now lossless.
[MINOR WEAPON BUGS]
– Updated the autobuy and rebuy scripts to support 2x flashbangs and reordered the purchasing order (in case of insufficient funds.)
– Added tracers to alt fire on Aug, Sg, Glock, and Famas.
– Set all shotguns except XM to semi-auto.
– AWP and SSG08 now also drop magazines
– (Thanks, SlothSquadron)
[MISC]
– Fixed a server crash (Thanks, Gamemann, for the report)
– Fixed bug where non-Latin characters could not be stored in config files.
[MAC/LINUX]
– Fixed bug where demoui, console, and other controls wouldn’t show an ‘X’ to close the window.[/quote]

Rumor has it:

- Panorama is a replacement for Autodesk's proprietary Scaleform that originally was introduced within Steam's Big Picture Mode. It's since been included as part of Dota 2's Source 2 hybridization. For info on Dota 2's implementation of Panorama, [url=https://developer.valvesoftware.com/wiki/Dota_2_Workshop_Tools/Panorama]see the Valve Developer Wiki[/url]
- An added bonus of the Panorama UI system, UI changes can also be picked up by services such as SteamDB's GameTracking, making the tracking of stealth UI changes much easier

- In autobuy.txt configurations for new players after today's update, armor with a helmet and armor on its own, in that order, has been bumped to the top, leaving defuse/rescue kits at the bottom
- Existing autobuy.txt configurations should not be changed however, so if you're not a loser and you're prioritizing a defuser, you won't be rudely awakened by an explosion due to a lack of a kit

- The string that explains the premise of Prime matchmaking [url=https://github.com/SteamDatabase/GameTracking/commit/1dba1e462676e4b61a817353ddfb554586b36df9#diff-3e8527c0a587cb050550196854ee49baL11972]no longer makes any explicit reference to having enough experience[/url] as part of eligibility

- GameTracking is fusing both this CS:GO update [url=http://blog.dota2.com/2016/07/the-international-compendium-update/]and another large Dota 2 update[/url], so you'll be seeing a bit of both worlds, so here's scripts, that one string change, and an overview as to what changed inside of the VPKs: [url]https://github.com/SteamDatabase/GameTracking/commit/1dba1e462676e4b61a817353ddfb554586b36df9[/url]

- Size is ~25 MB