Sure, but in case like this, both parties tend to blame the other, so at least I was hoping that D-Link will look into it, to be sure which side is at fault here. I provided the information to be troubleshooted not to be used as a mean to disregard the problem.
From what I gathered, it's because instead of keeping the a separated NAT list from the connection list, this router meshes them together and consults the whole thing each time going to these page, causing something to hang.
As for another HW option, if I were to do it, I would use a small form factor PC to build a router using freeBSD router for example. Using a Cisco at home is kinda over the top and is outside of what I was asking for.