P2Pool latency, should I host in a datacenter or at home? I read about latency on P2Pool being a bad thing. Is this latency between the miner and P2Pool, or P2Pool and the network, or both?

I am trying to decide if I should host P2Pool pool on one of my servers in a datacenter, or at home where my miners are.
P2Pool works differently from most mining systems - it aims to have a completed "mini-block" about every 10 seconds, so latency of the p2pool hosting server is critical - milliseconds count.

So it absolutely must be in a decent datacentre on a high-quality (aka not-cheap oversold contended junk) network, not on your home connection if you expect ever to get any mined income.

You'll also have to admin the server/os/software, apply patches and upgrades and generally maintain things which can be a full-time job.

I'd suggest you just join an existing one - find one "close" to your location - do a traceroute to it - the less hops and different networks the better.