I need to make a video debunking the horrible myth about beginners needing slower cubes, and the whole idea of cubes being too fast for someone. Basically, it comes down to this:
People who say a cube is "too fast for them" have become accustomed to a cube that is more difficult to turn to the point where getting an easier cube will "feel" faster. It just takes less effort to turn, which they aren't used to. This can happen to anyone at any speed. Beginner or advanced. My friend said my AoLong is too fast, and he averages 15, and I've been using the AoLong since I averaged 25. Personally, I would try to learn on the easier cube and let my muscles adjust to it over time. This does not apply to a cube being so loose that it feels unstable, that is a different topic. But I would love the fastest cube that is still stable, and I would recommend that cube to anyone at any level.
I believe (though I don't have a ton of evidence to support this, which is why I preface with "I believe") that most RSIs come from using cubes that are too tight and/or too difficult to turn. I've never had RSI even averaging a hundred plus timed solves per day during my peak of practice, and I believe this is due to me using a WeiLong or better from 50 second average on.