I generally find that noise gates alter the pick attack and sustain just enough to drive me mad, even expensive rack-mount ones that I used to use before the world went to pedalboards instead of racks. This, even though I'm very experienced at operating dynamics processors of all kinds.
On the other hand, I love traditional P-90s. The P-90s on my 594 Soapbar are so close to the original P-90s on my 1965 SG Special that it's pretty darn cool. I'd be loath to change them out, unless a noiseless P-90 was as good in terms of that vintage tone many of us love.
My solution is the traditional 'turn in the room until the noise stops', which is not always convenient, or combine both pickups. When recording, I often have to rely on de-noise plugins, like the iZotope RX stuff, or Waves NS, X or Z plugins. A small chore, but worth the effort to get the sound of P-90s into a mix (I guess I like that P-90 sound a lot).
On the other hand, Fralin generally makes a good pickup. Anyone tried his noiseless set with success? How vintage do they sound?