No tweaking here. Two production units out of the box. No down time for 6 months. Overclocked to 1.25TH/s.
If that's the case, & you're using bitmains cgminer - you're losing potential earnings. You should use kano's cgminer for the S5 instead as mentioned a page or so back

Edit: Just a heads up - Matt Corello has released an updated version of his excellent relaynodeclient with some huge performance improvements - p2pool users can benefit greatly by using his software:
http://bitcoinrelaynetwork.org/https://github.com/TheBlueMatt/RelayNodeNice stuff Matt

Well ...

P2pool solves the relay issue itself - since everyone on p2pool should be running their own node, p2pool distributes the blocks quickly amongst all the p2pool nodes - thus other non-p2pool nodes also get the blocks quickly.
Of course, there's a lot of p2pool nodes that are centralised, so that reduces some of that advantage ...