As an experienced network engineer who is comfortable with everything you’ve mentioned (PFSense, Unifi switching and APs, Mikrotik RouterOS and SwitchOS for routers, switches, and APs) I have several different points of feedback.
-
If you want to look at Mikrotik for switching, only use CRS3xx or CSS devices. Mikrotik has gone through several iterations in their switch setup. The first and most rudimentary is the setup for devices that aren’t labeled as a Switch - meaning the hEX S. On those the options are the most basic, because the device is intended as a router and the switch builtin is only meant to provide multiple LAN ports. The second is CRS1xx and CRS2xx devices, they have nearly all the features one expects from a managed switch, but have to be programmed via the Switch menu, which basically amounts to programming the chip yourself - for example to make a port be “untagged” or “access” for a certain VLAN, you have to tell the switch chip to convert the traffic to/from the VLAN for both ingress and egress, on two different pages. The third setup type is that for CRS3xx/CSS3xx devices. On these they completely rebuilt their programming so that everything is done via the Bridge menu in RouterOS mode (CRS3xx devices), and made SwitchOS version 2 (CRS3xx and CSS3xx devices) which is very streamlined and straightforward for purely switching use cases.
-
CSS devices, and the RB260 devices, only run SwitchOS. CRS3xx devices have the choice of SwitchOS or RouterOS. All other Mikrotik devices use RouterOS only.
-
While it is OK to mix and match devices from different vendors, I would not mix and match devices using RouterOS and devices using SwitchOS (the exception being if you decided to use a Mikrotik router instead of PFSense). While the networking principals are the same, the interfaces are very different. This means you should either only use RouterOS on CRS3xx devices (CRS328, CRS309, etc), or only use SwitchOS on CRS3xx/CSS3xx devices (CRS328, CRS309, CSS326, etc).
-
Using the hEX S as a media center switch is a bad idea not just for the programming as above, but cost wise. The RB260GS or RB260GSP is a better choice. Both run SwitchOS - however if you get old stock then you may get one that can only run SwitchOS 1 not SwitchOS 2. I don’t consider this a problem, but something to be aware of. Also sometimes these are called CSS106 instead of RB260 - they tried to rename them when they made them SwitchOS 2 compatible but it isn’t consistent or universal.
-
Hardware reliability of Mikrotik is the same as Ubiquiti. And generally software reliability is much better with Mikrotik, they have far fewer bugs and unexpected changes make it to their “stable” releases. The only thing I’ve had an issue with once, was when making a lot of changes quickly via RouterOS, I think it missed applying one of the changes to the switch chip and I had to reboot it to get it working properly. But once it was applied there was no issues. Also this was on a CRS125, so I have no idea whether that could happen on a CRS3xx device.
Your primary choice of CRS328 + CRS305, and secondary choice of CSS326 + CSS309 are both fine. As I said above the hEX S is something I would avoid, use the RB260/CSS106 devices instead.