For starters, I don't think you will get OPNsense, pfSense or the likes running on OTS router hardware. So, if this is what you intend, there is not much choice.
Then it depends on your requirements. If your homelab lands in the area of 95% of the typical use cases, you will be very fine with OpenWrt or Tomato, or actually even most original firmware.
Unless you bought something that is ridden with bugs and will not get updates, there are most certainly no noticeable benefits of running an alternative firmware. (Things like bufferbloat come to mind, I prefer control over my buffers, but good routers firmwares also do this quite reasonably).
Another difference: getting OPNsense/pfSense running (and well maintained) will require considerably more time and effort, than OpenWrt or Tomato.
Actually, for most soho/home users I would recommend a FritzBox. They are really packed with features, are well updated, zero hassle. Unless you really, really need something more exotic, they will save you lots of time and money. Also: automatic updates (configurable).
There is also MikroTik. Slightly more expensive than FritzBox, also packed, but slightly different audience (larger networks, less "user-friendly"...).
Disclaimer: I have a FritzBox running PPPoE passthrough to an OpenWRT router running on a NanoPi 2RS dialing in over PPPoE, with a MikroTik CRS112 behind that running only as a switch.
I have my reasons for that setup, but the time and money I wasted on that setup is really difficult to justify to an outsider (and sometimes to myself). The FritzBox worked really, really well.