LTspice Vs Matlab - Power electroncs
Everyone has their own preferred simulation tool depending on what their background is and what they are simulating most often. You can get Almost all simulation tools to simulate any circuit(within reason) some just are a little easier in some scenarios. I would suggest you look at what simulation software the people around you or the people that you are working with are using because they can help you when you run into issues. They can also give you circuit files much easier then. 

P.S. I prefer PSIM to do power electronics simulations. I use PSpice(or LTspice) if I have to give the simulation to another engineer. I use MATLAB if I want to iterate through many different component values to make a circuit work.