Not much help as I've only used pfSense, but I'd say that your list of pros and cons for it is about right.

It's definitely fast (given sufficient hardware) and stable, which is the main thing, of course. My uptime at the moment is 244 days, and I don't think I've ever had a crash.

Updates are few and far between, especially if you don't install beta versions. I'm on the latest stable release, 2.4.4-RELEASE-p3, which was released in May last year, which was the last time I rebooted the server. The lack of security updates does surprise me a little bit -- I'd kind of expect there to have been a CVE that would have needed a new version release in that period, but I don't follow those things closely so maybe it's all fine?

I do find the UI a pain point, not so much in design as in terms of helpfulness. Even simple stuff like defining static leases for DHCP clients usually ends up with me opening an existing lease in another tab so I can remember the right fields to fill in. 2.4.4 added the fq_codel scheduler for queue management/traffic shaping, which works well to keep latency low when your WAN connection is near capacity, but the traffic shaping 'wizard' in pfSense has no knowledge of it, and to set it up I had to follow a Youtube tutorial, and I still have no clear idea how all the bits I set up link together, although it seems to work. Some of that's probably my fault as I'm a home user who only does things occasionally, I'm sure if you used it every day it would be a lot easier.

Overall I can't fault it for reliability, but I don't much enjoy changing any settings when I need to. I've been tempted to move over to opnSense, but haven't got around to it yet, so I guess I'm interested as well if anyone has experience with both, and whether the grass really is any greener...