Via [url=https://store.steampowered.com/oldnews/233193]the Steam store[/url]:

[quote=Valve]- Improved matchmaking performance
- Improved matchmaker behavior for users with less-than-ideal ping levels. The matchmaker should now be quicker to put you in the best available region.
- Improved matchmaker decision making for cross-region parties
- Added error messages when being ejected from the matchmaking queue due to connectivity or authentication failures, rather than the queue simply silently vanishing
- Fixed the matchmaking settings dialog frequently failing to display any datacenters
- Fixed multiple cases of in-progress casual matches abruptly terminating or failing to be assigned any new players if the game server ever loses connection to Steam
- Updated the Mountebank's Masque, Courtier's Collar, and Harlequin's Hooves cosmetic items to fix issues with their paint regions

- Updated cp_gravelpit_snowy
- Fixed a script issue
- Improved performance
- Improved clipping[/quote]

Rumor has it:

- Size is ~20 MB