I have tried that many times, especially last spring when I was marking fish at the middle of the water column. It never seemed to matter. I think it is just too much hassle for what its worth. And because I only run one rig, I can use a sliding weight dropper which, in my humble opinion, is the only way to go. These spring fish are HOT fish and always seem to flinch at the wrong moment. The biggest springer I have ever caught happened only because I was using a sliding rig. I set the hook on the fish and it immediately swam over to my buddy's rig and the dropper line got snagged onto his prawn rig. He was able to reel all the way in and cut my dropper line and free eachother so I could fight the fish. If I had been using a double rig then I could not have been able to use a sliding weight dropper... and the fish would probably never been caught! Just my own opinion though. I have seen other anglers do very well on double and even triple rigs. For me...it is just too much to bother with.
-Coot