Broadcom, wifi : install openwrt might affect performances?

hi

Im wondering about install openwrt on two tplink devices :
archer c1200 v1
archer c2 ac750

I wonder, especially due to that page :

does free or proprietary driver, is still up to date choice? I mean without the proprietary one, does only the 802.11n wifi is only available?

thank you

Yeah, BCM wifi is a no go.

C2 appears to be Mediatek though?

This one is Broadcom ARM CPU and wifi5, so wifi5 part is absolutely not supported by open drivers. I would not put much hope in 2.4GHz being older Wifi4 that one could squeeze out wifi4 of whole device.

This is Mediatek, albeit very minimal spec device, still very well supported, likely RAM restricts it to dozen clients and flash does not permit installing any significant extra packages. Install process needs a lot of care, but very well supported. 2x bigger device (in antennas, ram and flash) costs about 20 bucks nowadays.