I have been testing different ISPs in my area and found they all suffer from a constant packetloss issue. There is a new setting in CS2 that shows connection problems, and even though it's showing a connection problem and 1% packetloss most of the game, the results at the end of the game only show 2 dropped packets. It looks like the console results are unreliable and hide packetloss.
I think the solution is to use a "tier 1" provider. This includes AT&T, Verizon, and T-Mobile in the USA. They aren't available in my area at this time so I'm exploring different options, such as connecting to a VPN with tier 1 routing.
Sorry for the delay... If you're still looking for this info, try these settings:
In BIOS, disable power saving features, SMT, and hyperthreading.
In Windows, using Process Lasso on performance mode and highest performance profile should take care of the rest.