I like PowerPro...with a 12" leader of Fluorocarbon (or wire when Northern fishing)...and I always use a swivel.
With all the "stuff" in the water"...I think it blends right in. I do prefer a small black swivel over a bright one.
I really doubt fish recognize a swivel!....If they did...won't they recognize what the big curved, pointy thing coming out of your bait was!!!
Edit: I don't use a leader any longer than the distance I want between my lure...and the rod tip...so I can cast it without it running up into the guides all the time. I use as little as 6" for crappie/bluegill. Probably a foot for bass in clear water. When our water is off color...I just tie directly to the PowerPro....and yes after awhile with small lures I get some twist. Most of the time if you cut off the lure and troll the line behind the boat for a couple minutes the twist goes away.