To power condition or not

I think you have answered your own question, why don't you try both options and use your ears to tell you what's best. I envy you as I had the passive 40s a few years ago and loved them so much I bought a pair of active 100s to replace them . ATC make fabulous speakers especially if you like your music at real levels.

Try both. I have never had a problem with ATC Actives - dead quiet even with your ear right over the tweeter. It is crucial that you use XLR - a good cable in Canare Star Quad. If you use inferior RCA and adapt that to XLR adaptor then you can of course expect a much higher noise floor.

Whatever way you choose to go, get a couple Perfect Path Technologies E Mats to put on the inside of your electrical service door.  They will improve the sound of everything in your audio system as well as your video and all things electrical in your home.  They are the type of thing that once you have them and hear and see the improvements they yield you won't be able to do without them!