I'm on 100/100 megabit fibre connected to the ISP's switch (upgradeable to 1gb/1gb)
I work as a network specialist, I have both tools and equipment to test things out.
I even brought home a bad-ass Cisco firewall (Cisco ASA 5555-X) to do packet inspection, and to rule out my firewall/router as the cause or not.
It's very true new releases of firmware/software often run into trouble, in this case I tried two different version of the intel firmware, and they all behaved the same way.
I used to have one disconnect ever 15-20 minutes, now I have been playing almost a week every night, with only one disconnect.
I remember on my old I-7 930, I set affinity to one core, and set Aces High permanently to "above average" in both I/O and CPU, using a free software.