My previous experience with Simplicity Studio was around three years ago, and It was not a good time. I think I posted a rant on here about its problems and uninstalled.
Having reinstalled it recently and doing a new project, I am very happy! The interface is clean and intuitive, and most everything I've tried "just works" without confusion. The SWD debugging works every time.
Thanks devs, for making this IDE great. I take back all the bad things I said back in 2014.
Thanks for the positive feedback @caiannello!