Are you saying that you possibly have a BAD ROUTER because its performance equals a D-Link router that is performing as expected?
I don't know what D-Link router you are trying to compare the Orbi to, but Orbi is generally used to get better Wi-Fi throughout a home, i.e. eliminate dead or slow spots, by having the a router and satellite(s) offer better coverage area in a large space. If a single router is giving good performance in all areas of your home, I'm not sure why you would want to go from a single router solution to a router and satellite pseudo-mesh solution.
Not sure what your results are. But on a 100 down / 100 up internet connection with Orbi, you should be seeing all of your up and down speed on any single ethernet connected device (as long as its not an old "fast" ethernet port) and on any single 802.11AC wireless device.
I would try with the Ookla Speednet App from windows store on Windows 10, or Mac at http://www.speedtest.net/apps/desktop
or for mobile at http://www.speedtest.net/mobile
