I am doing quite good with 
ParkingPanel. I switched from DomainSponsor in early October and my revenue per month increased by about 300%.
My RPC on all domains is above $0.1 some are even at $0.9 
If I had time to build something on all those domains I sure wouldn't park them because I could do a lot more with real content on them but for doing nothing right now I am satisfied with the result.