I nominate A-lex-W (http://hdyc.neis-one.org/?A-lex-W ):

• 520K changes per 6 months
• 462356 nodes created per 6 months

Any bets on numbers when he finally celebrates first year in OSM?

Based on his edit history, I would say he experiences lag during mapswipe more often and possible solution would be to disable filling (W) automatically during map move.

PS. I also discussed auto-save during map move, but I’m not sure if importance of this feature was understood correctly, so I bolded it now: https://github.com/openstreetmap/iD/issues/2749#issuecomment-135950771