I somehow have a hard time believing that you can feel the performance of the tcp stack while browsing of all things in a VM, are you sure it can be attributed to that?
Had a wicked issue where a firewall was inspecting DNS requests and causing them to take almost 10 seconds to complete. Was hell on the SIP phones, and browsing the Internet was... Interesting.
Why not the TLS implementation? The video drivers and their kernel interfaces? The OS' process scheduling? A dozen other things that might be responsible for the perceived performance difference to one degree or another?
It feels like gamers who blame 90% of multiplayer issues on "the netcode".
It'd be different with data looking specifically at TCP connection establishment timing without a bunch of other stuff involved.