Funny you should ask about the swivel...I use quick snaps.
I was fishing on Scugog yesterday for crappie and was thinking about the Quinte Strategy thread that was posted the other day... as it was something I was going to reply to already.
Yesterday I had lots of active fish swimming around on the sonar but was only getting the occasional bite and fish. Thinking of the swivel question I decided to remove all the quick snaps from my lines and tied directly to my lures. Well the results were immediate. It did not matter what line went down the hole the bite was on. I don't think the snap and swivel necessarily spook the fish but it definitely affects the action of the lure.
I'm not sure why I started using snaps because I didn't always. Funny enough, spots that use to me more productive I thought were winding down over the last couple years. Maybe I got it wrong and really it was me, and the way I was presenting my bait/lures to the fish? Tell ya what though, I am no longer using snaps!
The biggest advantage to the swivel is to help eliminate line twist...also the convenience of switching lures is right up there. I use a bearing swivel higher up on the line between my braid (main line) and flurocarbon leader to help manage the line twist.
So definitely more work not using a snap/swivel...just means a little more effort involved... or more rods with specific setups/defined roles. More rods you say!...well it doesn't take much to convince a fisherman that he needs more rods that's for sure! At least not this guy