If I was getting this for an EDC, I'd go with the EX10 because its slightly smaller. If the P1D was still an option (with an updated 3 mode, similar to the L0D to LD01 update), I'd probably go for that instead. Also, the EX10's knurling gives it far better handling than the PD20 (necessary in an EDC, IMO).
If I was just going to add another flashlight to my never ending collection, I'd probably go for the PD20. Other than the superior efficiency, it has a better beam (when comparing Cree models), it can use L2D/L1D/LD10 bodies, and has a more proven durability record.
The only other deal breaker is RCR compatibility. Fenix's tend to lose lower modes until the cell is used up. The EX10 supports RCR's, but they don't have as flat of a regulation curve as Fenix's do on primaries/NiMH.