Those of us who have been playing for more than 30 years will remember the old scale of doubled non-vulnerable undertricks: 100, 300, 500, 700, 900 etc.
I feel that the 1987 change (1993 for rubber bridge) whereby the fourth and each subsequent doubled undertrick cost an extra 100 points was bad for the game. It has certainly had a noticeable impact on the attraction of "taking out insurance" as well as ruling out such coups as voluntarily playing in 1NT doubled down seven (are you reading this, Richard Granville?) or taking a seven-level save at favourable vulnerability with virtually nothing.
How do others feel?
Benefits include:
Plus... it's free!