Using 80Mhz channels I found the default configuration never exceeded 200Mbit/s using iperf. For me "reasonable" is closer to 800Mbit/s, which is roughly the theoretical limit for 80Mhz with 2 spatial streams. I run my tests with my devices sitting 1 meter from the AP. This is on a hAP AC, and like I said, I get much better performance (close to the theoretical max) running OpenWRT on the same unit. I have had similar issues with the RB4011 and cAP AC, and in both the NYC area and suburban Virginia (so it is not just an issue of spectrum crowding in the city).
Yeah, that sounds a bit slow. I suggest checking if faspath and fasttrack is working.
I remember that when I had hAP AC using firewall rules inside lan, it also did not go much faster. Good indication was CPU usage. If it used 100% CPU at ~200Mbit/s then it was firewall slowing things down.
With my 5 year old Mikrotik hAP AC I am able to get up to 500 Mbit/s on lan.
And my old phone now shows 250 Mbit/s on speedtest.net both directions.
How much more are we talking about? Have I missed some big hardware upgrade recently?