I always take longer to finish a plane than the estimate. Heck, Sometimes it takes me longer hunting for my misplaced Xacto or pliers or glue than the
time they say will build the entire plane. I must be awfully slow (but I do assemble well), and since my 80th birthday is this month, maybe it is
old age. They are a lot of fun to assemble, though, so don't really mind the time spent. The quickest that I have built was the Escapade (In my opinion a superb
ARF) and the Kyosho low wing Calmato (also an excellent ARF). While the Revolver was a little more involved, the quality of this plane was also exceptional.
If they estimate, say, 12 hours, I usually can count on 24 to 30 hours, so doubling the hours works for me.