I have been asking vendors to hold off submitting Broadcom-based MU-MIMO routers until they have working MU-MIMO and the DIR-895L/R was part of that embargo. But D-Link said its MU-MIMO now works, so I let them send it in.
The short story is I confirmed that the DIR-895L/R actually does use MU-MIMO frames. But the percentage of them is so low, total MU-MIMO throughput is lower than total SU throughput for multiple devices. I tested only up to four devices with the results shown below. The result is so bad, I'm not bothering to enter the results into the Charts.
DIR-895L/R MU vs. SU total througput vs. STA
The DIR-895L/R has done nothing to change my recommendation to not buy Broadcom-based AC3100 or AC5300 class routers at this point if you need working MU-MIMO.
I've put Smart Connect testing on hold because the method I've been using is cumbersome and doesn't really test whether the extra 5 GHz radio in "tri-band" routers really helps increase Wi-Fi capacity in busy wireless networks. I am planning on replacing it with a wireless load test that will better test wireless load capacity of any router or router system (I'm looking at you eero, Luma, et al.) Stay tuned.
If you're considering spending top bucks for a tri-radio router, keep in mind many users end up switching Smart Connect off and managing connections to the three radios manually.
The days of tri-radio routers may be numbered, folks. Now that NETGEAR has stepped into the multi-AP "whole home" Wi-Fi system game with Orbi, you can be sure Linksys and eventually D-Link and TP-LINK won't be far behind. With prices in about the same $300 - $400 ballpark as the current going rate for AC5300 products, multi-AP systems should make you think hard about which way to spend that much money.
While both approaches throw more radios at improving overall Wi-Fi capacity, multi-AP systems address have the potential to better address wireless coverage problems that three-radios-in-a-box solutions can't. This is because the best way to improve 5 GHz coverage is to reduce the distance between AP and devices, which multi-AP systems can do.
But balancing bandwidth use between backhaul (AP-to-AP) and devices is tricky business. Add in band-steering, load balancing (AP steering) and "seamless" roaming and the new guys have a lot of heavy lifting ahead.
If you're still convinced a big honkin' router (BHR) is the way to go, the DIR-895L/R certainly fits the bill. It may also impress your friends if their taste runs to gamer-meets-goth with a bit of sports car thrown in. The DIR-895L/R's wireless performance runs with the pack and it will even save you a few bucks over its competitors. But if you're looking for more router features, the ASUS RT-AC5300 or NETGEAR R8500 will be better choices.