It's Halloween in TF2, which is the best time of year in game. This year's event has been pretty good. Not perfect, but pretty good.
Things I liked:

They opened access to Halloween maps early this year. Most years the event starts in mid to late October, but this year they opened access to maps on October 1st. Contracts and cosmetics didn't start til mid October, but it was a nice warmup to do the maps before then.

Two new maps. Both look great, and play pretty well too. Two is a nice number as well, since its enough for everybody to learn the layouts, and not so many that you don't fully learn or enjoy them all.

Contracts were reset. It would have been nice to get new contracts, but at least we get to (re) do contracts. I do enjoy going through the old ones. None are too grindy, and its a good excuse to sample them all instead of just sticking to your standard few.

I've had better luck transmuting this year. Last year I only had 2 good transmutes (parrot head for demo, unicorn hat for all classes). This year I wanted to get one or two more animal heads, and I'm very very happy to report I got a fly head for engie and the chicken kiev for Heavy! I was a bit disappointed how badly the kiev clips with lots of hats, but it looks great with the unicorn hat so I'm running that now.

Some of the new hats look great. The sugar skull for pyro and the raccoon mask for Soldier in particular.

The new unusual taunt effects look amazing. The spellbound/arcana ones in particular, and they brought back the moons this year too. The only really weak one to me is the static mist one, and even that isn't that bad.

The hat unusual effects are a mixed bag. Fifth dimension and some of the wispy flame ones I like. The vortex ones are pretty meh.
Things I did not like:

No spells. I guess that makes existing items with spells that much more special, but I was kinda hoping they'd bring them back. Even if they were untradable.

Some of the new crate hats should have been halloween restricted. Some really don't fit the aesthetic of the game when its not Halloween. Like, the bread biter is fine as a Halloween item, but seeing that in April in a non-Halloween server is going to be jarring. It feels so arbitrary which items are halloween restricted and which are not.

Old unusual effects are not unboxable. I guess that's good for me, as it protects the value of my 2 remaining unusuals (darkblaze modest scrap, and dark doorway antarctic eyewear). Still, it would have been cool to see some of the classic effects on the new hats and vice versa.
Overall though, its been a lot of fun. Its nice having a contract or two to do every night, the transmutes feel like a cheap crate unboxing, I've got 2 nice animal heads from transmuting, and the overall aesthetic of Halloween is always fun and in a weird way comforting.