1) This is centralized so you wouldn't have to edit on every PC/device 2) It's a bit tricky to edit the hosts file on an iPhone..

You can put a hosts file on your router. That way it is automatic to ALL devices, no need for DNS tinkering.

Only if your router supports it. Many ISPs provide locked down routers with no access to hosts, no ability to change DNS servers, etc.

I'd just get a new router or DD-WRT. If you are spending all of the money on a Raspberry Pi and all equipment you should probably get a router that is free*.

Hell, add a wifi dongle, and now you have a kindof-good router.

re #2: it's only two steps to install a proxy-based adblocker and then set a proxy for your internet connection. Same goes on Android.

A hosts file on a router would be much faster than anything else. Nullrouting packets before they even enter your LAN is possible the best thing you can do.

A filtering proxy takes many more CPU cycles than this solution.

This is a lot more efficient.