"I did lose 18 lbs in the 10 days and 5 came back after rehydration. In the water fast I lost 40 pounds in 40 days and 15 came back after refeed."
It does appear that you lost more weight/fat in your DF than in your water fast, if we take into account the number of days?
"Also, for me - on a water fast after about 3-4 days I get into heavy (140) ketosis. On the DF the ketosis stick never registered above 80."
That is curious indeed. I am sure you read the DF posts in FastingConnection. Almost every DF faster there claimed that more fat was mobilized while they did DF since the body needed to create water from fat.
You said you had good energy during your 10-day DF but were tired in your water fast. Could it be your body was very good at using ketones during your DF (so you had good energy) and thus fewer ketones were expelled through urine?