The most popular cubes with magnets right now are probably the Gan356 Air UM, the MoYu WeiLong GTS2 M, and the Valk3 M. They have an interesting feeling that provides the right amount of stability to avoid most lock-ups while still allowing you to turn fast. It's kind of something you need to try to understand, so if you have any future competitions, that'd be the best place to try some out before you buy them. Most people who have tried magnetic cubes seem to prefer them though, so if you don't have any competitions coming up and you're looking for a new cube, I'd give a magnetic cube a go.