good update.
First of all, I can see why they buffed the phlog. Before you yell at me and say IT WAS OP BEFORE AND OP NOW, theres reasons. Yes, its unbalanced and was always unbalanced in pubs. In comp, it was awful. A comp pyro is mostly used for airblast. They airblast stickies off points, airblast rockets from kritted or ubered sollys, and play a more defensive role. Valve is implementing a matchmaking competitive system, so they try to make weapons viable. Before the phlog was terrible in comp, and while it still is pretty bad, it still could be used a bit more offensively.
Second of all, degreaser was op before. It was pretty much a direct upgrade to the flamethrower. Too lazy to explain and justify nerf, so heres this vid by b4nny (you may or may not know him hes a popular tf2 competitive player)
http://www.youtube.com/watch?v=Y5pZgph_ZaU
Third of all, the jag still is really good and the best wrench for startup. Most people use it to build their buildings then suicide to the stock wrench. Before, it was a direct upgrade
Fourth, thank GOD they nerfed demoknight. Before, it was annoying, overpowered, and completely broken. (the shields had completely ridiculous defenses, and the zatoichis max health kill was completely broken)
Fifth, they made medic more fun so more people would play it. The crossbow buff was pretty good, and the other buffs were also really good.
Sixth, they encouraged team work with the extinguish giving health or recharge with jarate, airblast, and mad milk.
There's a lot more changes i could go into, but it would take an hour to type up and i cant think of them on the top of my head but id give this update a 9/10 or an 8/10 for some of the more pointless but minor nerfs