I tie directly to my jig/lure for icefishing (except pike) and that's it. All other times I use a snap swivel because I change my rigs/lures fairly often. I don't think that fish get too spooked by a swivel when you have 2' of willow branch or 3" of lure on.....lol. It might make a difference with a jig but the walleye and occasional pike that I catch on jigs in the summer don't seem to mind the swivel too much.
For those of you tying your line right to your lures.....
Don't you ever have any problem with your line getting all twisted and prone to coiling up when using lures?