I have used IB’s TWS and their mobile app. The TWS felt clunky, but good. Their mobile app was far better. I was using on a Mac.
The best? I would say ThinkOrSwim (TD Ameritrade) is the best platform by far. The founders of ToS, went on to find TastyWorks/TastyTrade, which is more suited for options trading.
Is it worth switching from Zerodha, for scalping - can’t say.