Big thanks to Coreplayer2 and others for keeping the firmware tcz's up to date ...
I had a problem and didn't even know it! My budget Acer desktop uses a realtek 8168g3, but the kernel does it's best but loads an 8169.
That gets me functional, but results in an intermittent connectivity, slowdowns etc. Thing is, with TC being so small, I didn't really notice until I had a long browsing session..
Was it TC 9.0? My ethernet<>wifi dongle? My cellular modem? Dillo browser? My own misconfiguration?
Finally looked at dmesg, and there it was - watching the kernel go through hoops to get me some sort of ethernet connectivity after a bunch of errors, helpers, more errors....
Moral: if you've got a realtek ethernet card, and are suffering delays, sluggishness, etc, check out the firmware-rtl_nic.tcz and see if might apply to you.
And nice enough, I didn't even have to blacklist the 8169 driver - it seems to get out of the way when the firmware is loaded.