When you need to shape even more bandwidth, routers based on the Marvel XP Armada chipset do very well. I flashed a Linksys WRT1900ACS with OpenWRT and was able to shape about 600-750Mbps before it ran out of horsepower.
I love my ER-X, but once I got my gigabit connection it can't quite keep up compared to plugging directly into the modem. It's close enough that I'm not looking to replace it, but the next time I need a router I may go the NUC build your own route.
I have done this at my parents place with a cheap Intel Celeron based computer with a single network port, but 2 logical networks with vlanning. One is for their personal network and the other is for their guest suite they offer through Airbnb.
It’s only 20MB/s fibre, so not much cpu power needed. The no name computer cost less than $250, came with a 60gb SSD and I put pfsense on it.
Note the comment "the actual rate limits will be set to 95% of the specified value". That explains why I saw a 5-10% dropoff in throughput when I enabled it with honest numbers.
I am always happy to hear of a bloat free connection.
Results from the DSLReports speed test [2], using the same router, the only difference being turning smart queue on:
Smart queue off: https://i.imgur.com/zeY4rTd.png
Smart queue on: https://i.imgur.com/jfHpiFb.png
Notice the improvement in bufferbloat score from D to A+.
Subjectively, I have noticed the connection seems more responsive and there no longer seem to be latency spikes when utilising all the upload bandwidth.
It’s certainly worth considering bufferbloat, if you suffer from latency spikes when using all your upload bandwidth (I used to suffer from this a lot more, when I had an ADSL connection, with only 1 megabit upload).
[1] https://www.ubnt.com/edgemax/edgerouter-x/
[2] http://www.dslreports.com/speedtest