"Playability" is entirely subjective to the player. Many people prefer satin poly finishes, oil and wax finishes or just raw wood. However there are some people that do prefer gloss finishes. Similarly the divide between poly and nitro is more or less 50/50, there's really no clear winner.
And yes, get two pieces of 1500 wet & dry paper, using one totally dry first and then use the second very slightly dampened with a little room temperature water with a tiny, tiny amount of soap or washing up liquid in it. The dry piece will be what really takes the gloss off, the wet piece is just to smooth out any particularly deep scratches. You may be fine with just one dry piece of 1500 though, it really depends on how careful you are and what the finish is like to start with. If you're trying to take the gloss off a really thick finish then it can be a better idea to use the steel wool, or go up to 1200 grit paper for the dry stage.
For really, really thick gloss poly finishes, like those you get on production guitars from China and Korea, you can start off with 800 grit paper, then use 1200 or steel wool to smooth it off. If you're buying a Warmoth neck with a Warmoth finish though, it'll never be that thick.