There are differences however including most notably more adjustability in the form of Titleist’s SureFit CG technology that allows for more specific spin rate and launch angle tuning. The TS3 also features a more traditional pear shape and tends to produce more of a mid-launch as compared to the TS2’s higher launch.
Among those I’d start by looking at models from Bettinardi Evnroll SeeMore Happy and Bloodline. Each of these companies make high-quality products at varying price points. Furthermore they can perform exceptionally well provided you find one that fits your stroke eye and feel preference.
None of the above matters if you can’t aim your putter correctly Experiment with offset and straight-in hosels — you’ll definitely aim one type better than the other. Then check the alignment marks. Do you prefer lines that run parallel to the target? How many lines? These are important questions that can best be answered through a proper fitting.