That's three straight CSGO updates for Valve that address some of the biggest issues players have had with the game over the last few years. But they aren't doing away with those issues entirely.
Valve are significantly reducing unarmored "aimpunch," the amount your screen moves when hit by a bullet. In the past, completely unarmored players would experience aimpunch after being shot anywhere on the character model. Buying a vest would prevent aimpunch from bodyshots. Buying a helmet would prevent aimpunch from headshots.
Both pros and amateurs have complained about aimpunch for years. It is not a skillbased quirk, and is more of an arbitrary economic management element, but not one that requires any depth of strategic knowledge. Valve is not removing aimpunch -- it will still occur with body shots -- but are promising to "significantly reduce unarmored aimpunch." The specific stats of those reductions have not been made public yet.
Valve are also cracking on with their rework of pistols, which have been unbalanced for a long time. Previously, they redesigned the strengths and weaknesses of the Tec-9 and FiveSeveN.
This time around, they buffed up the Glock and completely redid the P250. From the pre-release notes for 188.8.131.52-rc1 Beta depot:
"Glock: Slight adjustments favoring accurate players who close the distance to their opponent.
- Increased base damage
- Reduced damage at longer distances
- Slightly improved accuracy while firing rapidly
- Slightly improved accuracy while moving
P250: The P250 has been adjusted to reward longer-distance engagements, particularly against unarmored opponents.
- Increased base damage
- Reduced armor penetration
- Improved damage at longer distances
- Reduced accuracy while moving"
According to Nicholas "SlothSquadron" Crew, creator of the CSGO Weapon Balance Mod, "these changes seem to lean closer to being a buff for the Glock and a complete shift in roles for the P250."
"The Glock is significantly more reliable," Crew writes, "than it was previously when spamming and tapping, and the increase to its damage not only means that one hit kills on pistol round will be slightly easier, but also when in a full save, the Glock can actually much more reliabily two shot armored opponents to the head. The only real downside to these changes is that the Glock's damage at range is slightly reduced, but with the improvements to its accuracy chances are you'll be hitting more shots at long range as you'll be able to tap quicker."
He switches gears, "the P250 on the other hand seems to have completely changed roles. It no longer one hit kills armored opponents, making its usefulness as an eco gun significantly less. Accuracy when on the move has also worsened. Instead it seems like Valve wants the P250 to be a gun that's used against unarmored opponents due to its increased damage against them. This could mean P250 buys on pistol rounds might become a common sight, and when combined with the lessened aimpunch this update brings, armor is less of a necessity on pistol round."
You can find Valve's full beta notes here.