Yeah, for the first time it's true gigabit. Results from iperf:
Raspberry Pi 3B: 94Mb/s Raspberry Pi 3B+: 285Mb/s Raspberry Pi 4B: 930Mb/s
(Nitpicking: real gigabit Ethernet over USB 2.0 is impossible, USB 2.0 is limited to 480 Mbit. Still better than 100 Mbit Ethernet.)
Yeah, I know, that's why the old one sucked.
[EDIT] sucked is harsh—it did what it said it would. It sucked if you actually wanted to use the Pi for serious IO of any kind. USB2.0 and Ethernet limited to USB2.0 speeds was no good at all for that.
I... may be getting a few of these. I'd skipped the 3 on account of how the 2 turned out to be kind of a bust for me (have three, none in use...) but the faster IO and higher RAM options makes these one hell of a lot more useful. At 4GB you can kinda use the web, even, as long as you shy away from using more than one or two "web apps" (to include Electron) at a time.