First rule buying a router/wifi ap: make sure it is supported by openwrt
The only routers i have are or have been supplied by my isp. My main wifi is handled by an old unifi ap. If i was in the market for one, openwrt would be a requirement
Auch! First thing i do when / if changing provider is ask if their ārouterā can be programmed as bridge only. If not, then goodbye, brotherā¦
I have my own router, (a number of them actually, connected in a Mesh) which is ājust a bitā more powerful than that cheap sh*t from providers which is very good on paper, but generally a piece of cr**p in real world.
First rule buying a router/wifi ap: make sure it is supported by openwrt
True. I only have Asus routers which can be loaded with Merlin custom FW (asus based, but heavily customized and upgraded). Having stock FW is good enough for ānormalā user only. I guess that this makes us āabnormalā users thenā¦ 
(ok, letās say āadvancedā).
While the router often allows you to export DHCP configuration, unfortunately, you can rarely import it. Manual modification of IP reservations is necessary.
True, but if you have exactly the same model router you would be able to do a full config backup/restore 