There are very good performance indications on the Mikrotik website if you bother to scroll down far enough
https://routerboard.com/RB3011UiAS-RM
Ethernet test results
RB3011UiAS-RM IPQ-8064 All port test
Mode Configuration 1518 byte 512 byte 64 byte
kpps Mbps kpps Mbps kpps Mbps
Bridging none (fast path) 325.0 3,946.8 939.8 3,849.4 1,530.2 783.5
Bridging 25 bridge filter rules 325.0 3,946.8 384.2 1,573.7 348.6 178.5
Routing none (fast path) 325.0 3,946.8 939.8 3,849.4 1,437.6 736.1
Routing 25 simple queues 325.0 3,946.8 419.6 1,718.7 419.7 214.9
Routing 25 ip filter rules 202.0 2,453.1 204.1 836.0 188.4 96.5
Currently using an RB3011 myself, RouterOS was a little flaky when they first came out, lots of port flapping and network loop detected error messages but seems to have firmed itself up since 6.34
If you don't need the rack mount then the new Hex r3 seems to be a very hot potato at the moment however they have just done some small upgrades to the cloud core range as well which would be much more "industrial" if you want to spend enough to feel justifiably more of an upgrade.