I don't own any blades or KNC, but with BFL and few USB erupters it's working pretty fine.
And I'm running it on an old laptop. Uptime of the machine is 88 days now, bfgminer 39 days.

Setting up the p2pool itself was easy, most complicated part for me was the automation (like auto-restart of all mining related processes), and if anything happens (long term power outage for example), all I need to do is push the button and everything will start itself in the right order.
The only drawback is my crappy and unstable DSL connection. As soon as enough peers connect to me, it crash and come up with new IP address.

To get back on topic, I wasn't aware of this feature of GBT protocol in combination with solo fallback. It's brilliant .
Disadvantage of GBT is higher load on both sides (pool and miner), so I'm not sure that pools will support it if significant part of the miners switch to it.