In summary, a fun Christmas update was the wrong time to introduce a major rebalance.
While the changes did more or less put some of the classes in balance with each other, they also mostly removed the ability to casually play the game on solo. A lot of the changes made sense from a balancing perspective, but from every other perspective seem rushed and illogical. For example, reducing crossbow body damage but leaving its penetration; reducing handcannon body damage but leaving the penetration; making dual hand cannons less useful than a single; making pipe bombs extremely expensive, but leaving the demolition perk's capacity at eight pipes?
Any time a player prefers lower tier weapons over higher tier weapons (when they can afford them), I wouldn't consider the game to be properly balanced.
It also feels like the zombies are more aggressive. They used to come in waves, but now it's a constant stream. This has made the biggest impact on my personal enjoyment. It feels like the game strategy mostly consists of when I time my reloads, and not how I kill zombies.
But anyway, most important thing is the first sentence. C'mon, you ruined my Christmas!