>IMO for GbE to make proper sense they would need to add a proper SATA port.
Or USB3. I replaced the Pi I used for a file server with an Odroid XU4. Yes, it's twice the price but more than twice as good in this respect. I get full Gigabit bandwidth from a USB HDD. SATA wouldn't have made a difference here.
I expect for most people the lack of bandwidth isn't a huge issue but it all depends on your application.
I use one Pi in anger; a Pi3 running OSMC and it's good enough for that task.