What do you look for in damping factor?

It's been decades since I was up to speed on damping factor, so I'm interested in knowing what all of you look for. And—if you're so inclined—why. I may be in the market for a new amp sometime soon, and I'm no longer sure how much weight to give to this spec. THANKS.
-Bob

P.S. Speakers I use are Maggie 2.6/R, Spendor SP3/1P, NHT SuperTwos and PSB Stratus Minis (hey, I like them all, to one degree or another!).