For me, plenty, but a four-POP single-state network usually has different constraints on "scalable". However, I'd categorize it as one community-list per MED tier (i.e. if you just want near/far, that's two tiers, etc.) and one community-list entry per POP (or group of POPs, if you have some grouping logic embedded in your internal communities).
I think Pete is saying that as long as you aren't a control-nazi, its a good system. :)
Given that constraint, I wonder how of NANOG it applies to. ;) Deepak
