I have chosen the route of single tapping over alternating, but I see some advantages of alternating. Single tapping over 285 bpm is really fking hard. That is about my physical max for single tap. But some maps, I can do the pen just fine, and they still don't seem too fast. Then I see someone DT it finally, and they are alternating. I think this will be my next challenge for learning new osu! skills. I don't think there is one "best" way to play the game, but certain situations call for certain playstyles I believe. I am convinced that after a year of playing this, you have to be somewhat flexible in your play. If I could give you advice, it would be to learn as many thing as you can and do whatever works best for the goal you are trying to accomplish.
Hope this helps!