I just got mine today. Its an EF. Amazed at how smooth it is. Takes a bit for the ink flow to smooth out, but after that it is a pleasure to write with.
da_vin_ciAfter filling, let 3 drops out and wipe; nib is primed and ready to go. That said, piston-fillers should not have flow problems, so you might want to use some pen flush after you clean it next time. don't forget to rinse after using flush.