What was your average FPS before the update? If it was decent, it won't hurt to try reinstalling your TF2. Sometimes game files get messed up and redownloading them helps (at least helped me when I had issues caused by an update).

Also, please try that 64-bit Windows again, half of your RAM is pretty much wasted now.

http://www.reddit.com/r/tf2/comments/25pqha/tf2_freezing_windows_81/

It's caused by the latest Source Engine update (I'm on W8.1 too).

Garm3nFont.ttf is missing (i.e. required for KonrWings crosshair).
I imported it from an older version though and it's working.

Other than that, it looks great for me, especially the new scoreboard and counters.

Having the same problem recently. As soon as someone appears on screen, my screen gets jittery and I get huge mouse lag, it feels as if someone halved my sensitivity.

What I discovered is that it only happens on certain servers, while others are completely fine. So I guess it's either some server plugin or perhaps connection issues related to routing to the server.

I'm on Windows 8.1 64-bit, but maybe this will help you.
My overlay didn't work when running TF2 in compatibility with Windows 7. Check if you're not using any kind of compatibility mode. If you are, disable it. If not, try enabling it for different systems.

Another thing that would screw my overlay was mat_aaquality (not mat_antialias).

CM Storm Quickfire Rapid is a great choice for a tenkeyless. Or a KBC Poker 2, if you'd like your keyboard even smaller.

MusicBee, since I can't be arsed with configuring foobar2000 again after another OS update.
It's easy to configure, looks great (many skins to choose from) and only eats 70MB of my RAM.

I also use Spotify occasionally if I want to find new music.

This helped in my case, thanks!

Have you tried setting it to 70Hz instead? My secondary 60Hz monitor runs well at 70Hz (1080p), but not at 75Hz (full screen artifacts, bad quality, etc.).

Here's the update for 64-bit W8:
http://www.microsoft.com/en-us/download/confirmation.aspx?id=40909

Windows 8 is great for me, alttabbing and dual-monitor performance is very smooth. Metro really isn't as bad as people say, just spend a few days on Windows 8 and you'll get used to it.

No, not really. Refresh rate seems quite fine on my 6850 with a second monitor running at 70Hz. What I'm getting are occasional full screen artifacts (display shifting several centimeters horizontally, massive flickering, etc.). I recently found out it only happens when I overclock (Overdrive) the GFX card.

There's nothing wrong when I look at the pic you linked, it's all just dark grey.
I see flickering when I lower brightness on mine (70% or lower), but that's still only noticable on certain backgrounds. Have you tried setting the brightness to 100%?

I just googled some ancient forum thread. Is there anything close to your monitor that could cause unwanted interference or magnetism (like a cellphone)? I'm not sure if this applies to modern LCD panels though.

Also, are you still using your old monitor? I've had some dual monitor setup issues caused by AMD drivers.

Solid, thanks man.

Don't force 1080p if your PC can't handle it and you can't make it smooth.
Smooth 720p > choppy 1080p.

Other than that, I like:
-crosshair, killfeed and in-game sounds ON (not too loud though)
-please don't overuse filters and effects (especially slow motion), unflashy editing is great
-good/original (doesn't have to be electronic) music with occasional sync (don't sync every single frag)
-unusual plays/situations

Nickname: Lex

Stream: http://www.twitch.tv/lextf2

Comp: Pyro for Anasirenites/Pick up the paste (ETF2L HL div2A S4 and EU UGC Platinum S9), STHNC (Wireplay HL S10)

Country: Poland (stream should be 99% English though)

Info: I'll be streaming pubs, HL pugs/scrims/matches, some jumping. Anything, as long as OBS doesn't give me a hard time (I haven't found the perfect settings yet).