So a word of warning for those using older UniFi Security Gateways - just stay on PPPoE. 

Reason for this is there is a longstanding bug that’ll expose your whole router to the internet if you just change from PPPoE to DHCP. You’ll need to fully reset your router and reprovision if you want to do this and it isn’t worth it as it can do line rate PPPoE anyway. 

Many other routers (like the RB4011 @shindig) can also do line rate PPPoE and I would keep it using this for reliability - there is no point changing to IPoE here. Same with the Spark Smart Modems and almost every other router. 

Some routers, like Fortigates don’t have hardware accelerated PPPoE so can benefit here. But for the majority of other routers out there, there isn’t really any benefit for over PPPoE. 

…until Hyperfibre is involved.