Me personally, I use snaps but remove the split rings but I just re-checked KVD's book Secrets of a Champion and it reads:

"I prefer to use snaps on jerkbaits and crankbaits to increase lure action. I've found that line cinched to the split ring can inhibit the action on most hard baits."

"On jerkbaits, the snap provides a loose connection and gives the bait a more erratic action and gets me more bites."

"On crankbaits, especially the big baits in the summer time, I like to reel them down into the cover so they ricochet and suspend momentarily. The loose connection with the snap-just as it does with a jerkbait-gives it a little more action."

He writes he uses a Berkley Cross-Lock snap in #3 size. It's a 75# snap.

As far as removing the split ring, he writes:

"Don't remove the split ring; hook the snap to the split ring or you won't achieve the same action."

I see, good to know. so he is using the snap on the split ring to impart an action that was not there when the bait was engineered. hence "I prefer to use snaps on jerkbaits and crankbaits to increase lure action. I've found that line cinched to the split ring can inhibit the action on most hard baits."

but if one were to remove the split ring and just used a snap it would have the same action as the split ring. Thanks

snap = for ease of changing lures

swivel = to help free up the motion of the lure

Swivels are to prevent line twist. 

Too much hardware connected to the crank will end up reducing/dulling it's action.

I was just looking at those crosslocks at TW. Has anyone tried those Titanium smartlinks? Seemed to be a good idea.

"I prefer to use snaps on jerkbaits and crankbaits to increase lure action. I've found that line cinched to the split ring can inhibit the action on most hard baits."

Obviously KVD does not tie a loopknot.  A loopknot or a duoclock will produce the same result.  Advantage to snap is not having to retie ( no big deal) and having your leader last longer as it does not shorten with each new lure. Don't know if he fishes with a leader or not.