Solid but with a few querks.
The basic router functions are fairly easy and solid. However, the VPN section is tough. I spent hours working with D-Link Business support trying to figure it out. It finally came down to using IKEv2 in the IPsec protocol setup. The Windows 7 VPN client is IKEv2, but isn't mentioned anywhere in Windows. Then magically all the other settings we were collectively beating our heads about worked! There are continuing issues with in coming connections from some remote locations, but others work perfectly. I believe it has to do with issues at those locations. Working on it.
The only other issue is every time you want to enter the router you get a certificate warning in IE 11. You just continue, but it is a pain to deal with especially for something that should have been fixed long ago.
We were using a D-Link DIR-655 before, so I reworked it into a wireless access point only, and that allowed us to purchase the wired only DSR-250 at about $60 less than the wireless version.