When Korea buys Airbus rather than Boeing, it's very, very telling.
Really, of what? The products or the buyer?
As said by others, there's lot's of testing yet to do with the Pegasus and since it really is testing, some unknowns to face. But let's see 50 years from now which of these tankers has served their military purposes well. Boeing has an excellent record in that regard.
And best of luck to the Korean Air Force