@andriys and @chechito
My experiences with crs3xx routers were not good, some time ago I tried to use routers on my crs3xx and all corrupted the firmware after the upgrade, so routers don't work for me.
there is a miss-conception
CRS Line are switches no routers
the fact of using RouterOS does not imply you have to do Routing, as other forum member stated before, all switching features are available on RouterOS
you said you had experience with CRS2xx and that Line Comes only with routeros no option to choose between SwOS or RouterOS
I think The advantage of using RouterOS instead of using SwOS is from the management perspective, with RouterOS you have trafic and resurces Graphics, you have winbox, you have RoMON, you Have API, etc etc etc
I think you another kind of trouble
I am a consultant and i have many CRS 326, CRS 328and CRS 317 deployed on many scenarios working OK, the only issue is the performance penalty when download interfaces reach saturation point or when using mixed speed interfaces causing rx-overflow on uplink interface and decreasing performance
Important performance problem YES
BUT
i have not a single issue like you describe, No problem upgrading up to RouterOS 6.45.3, no corrupted firmware, no rebooting devices, no bricked devices, very reliable and stable operation
I have perceived so much stability that I take the liberty of doing updates remotely without problem, i manage several devices in different country's, zero incidents on upgrading
I am testing 6.45.3 to see if rx-overflow and performance is improved