I have heard about that as well. No idea how much degradation charging at 1A rather then .5A, but being able to charge a pair in 3 hours or less rather then 4 or 5 hours is worth it.
According to Mooch, charging at 0.5A as opposed to 1A may extend an 18650's life a little, but 1A should really be fine as long as your batteries aren't getting hot. It's 2A charging that will really heat them up and lower their life span.
How can we extend the life of our batteries? | E-Cigarette Forum