Great questions John. Can you fill us in on what your background is?
The most educated person to give you an answer is Joe Norris up at the Sonex factory. Joe created and runs the Sonex T-Flight program for people transitioning into the Sonex. If you'd like to see an excellent article that Joe wrote to explain some of the "catches" of people learning to fly a Sonex, go to the Foundation's webpage (
www.sonexfoundation.com ) and under the 'NEWS' tab (right side) you will see where the 'Newsletter Archives' are found. Read the November 2013 edition to find Joe's story.
To offer my two cents to your question, remember that everyone is different at getting a feel for an airplane, but as a general ballpark figure I'd say 5-7 hours will start getting you comfortable in a Sonex. The biggest challenge is mastering the sensitivity of the Sonex compared to a 172. Controls are much lighter which will be fun in the air, but getting a "delicate" touch during takeoff and landing will take a little practice. Once you get comfortable with the Sonex though, the 172 will be boring!