Agree totally.
Easy enough to unscrew the bolts, lower it some more and let the spring just hang there while you remove the cap, but a quick loosening of the two bolts in the bottom, remove the top clamp and a quick twist of the spring pops it out.
That way you don't have to lower the axle as much (or raise the frame as much, depending on your point of view) and, as Apogee said, you don't have to sit there fiddling with the lower bolts so much.
I just recommended the hanging method to someone today on the phone, but didn't have time to go through all the options (and kind of forgot anyway).
Either way works.
Paul