I use clips for all treble hook plugs -- crank, jerks, lipless cranks, topwaters.

Makes my life easier, and I still catch fish.  And most importantly, no lost lures or broken clips.  I think the line will break well before the clip would.

I agree 100%.  If you're using the right sized snap, it's going to be rated for over 50 lbs.  

The problem with snaps for most people is that they do not re-tie throughout the day.

Line on cranks takes a huge beating. Run your crank through some cover for awhile and feel your line.

If I'm on a good crank bite I might re-tie 20+ times in a day.

I don't know if they really effect the action, but sometimes I think they do and that's why I don't use them. Might be a mental thing though.

Do you put the clip direct on the crank or attach it to the split ring?

I just read KVD's book and he says use them. Enhances the action. He has over 2.6 million reasons to back up his claim.

He uses snaps( DUO LOCKS ETC) not snapswivels which absolutely ruin the action of a crank

I have used Snaps forever.  The only time I ever had a broken snap was when I was in the Florida Keys with my bass rod and hooked a tarpon. I had 40lb test but the swivel was bent straight