See, I do have a recent Mac, and my OS is up to date, and I find Safari relatively unsatisfying. It can be slow in loading pages, and will occasionally crash unexpectedly, both probably because of incompatibilities with Flash. Plus there are many sites, developed with IE in mind, that won't perform well under Safari. Some bank sites, for example, won't load at all. But they will work under Firefox.
Look, none of these solutions cost any money. So experiment with a few and see which you like best.