As to night flying, I agree with Mark's comment about the pucker factor.
The reality for me is that when I go flying (or go to do pretty much anything else I enjoy alot like sailing) and plan a day of it, I rarely get home on time. When the good times are rolling, who wants it to end? So I stay current for night flying 'cause I'm likely to be late getting home, and if I do get home on time it's gonna be at sunset (good for pics). Some times you'll want to leave at dawn or a little before, and so being night vfr current is handy there too. You'd have to have one heck of a good reason to start a long cross country at dusk or the middle of the night unless you are performing a medivac or something really urgent, not too likely in your KR. jg
