Easiest answer, whichever one puts the ball in the hole in the least putts possible. Putters are unique to each individual. I myself prefer a firmer feeling putter, it gives me a good feedback off the face. I’ve used both blade and mallet style putters and have found success with both styles. If you have not been fit for a putter before, I highly recommend you do. A properly fit putter will allow you to get the ball rolling much quicker and the quicker the ball enters its roll the more likely it is to hold its line. A fitting will cover proper length, preferred head shape and hosel design. Hosel design will determine the putters toe flow and the amount of toe flow is specific to each player. Once properly fit you will start seeing your putts roll in more often!