I tested today 3 different firmwares on manjaro (HD7970) 

linux-firmware-20150527.3161bfa-1-any.pkg.tar.xz (chosen because it was a bit
before the first bugs were reported with TF2)

This allowed me to play TF2 without bugs for ~30 min. Then I had the bug
(screen freeze, sound loop) but the system recovered fine after 20 sec with no
loss of performance. I still had a problem before and after the bug with the
mouse pointer which wasn't visible at all time.

linux-firmware-20131013.7d0c7a8-1-any.pkg.tar.xz

This allowed me to play for a good hour, then: bug + recovery after 20 sec. At
the fifth bug the screen simply hanged, TF2 and steam crashed. (had to
ctrl+alt+f2). This one didn't have the mouse bug. This is the most stable TF2
experience I can get.

linux-firmware-20130725-1-any.pkg.tar.xz (earlier firmware available in the
repo)

This one crashed after 2 seconds loading the first map.

The first two firmwares also seem to have fixed the same bug which was present
in "Victor Vran" (same symptoms, screen freeze + sound loop).