Before my Yamaha's, I only used Startron and I have to day, my old 2 stroke benefit was better performance, less fuel and smoking and better idle. The plugs were cleaner as well. In addition, I did also switch over to full synthetic 2 stroke oil.
Now, with my Yamaha's, using Ring Free, Startron and Amsoil Full Synthetic 2 stroke oil. At the price of 2 stroke oil, I can get the Amsoil cheaper than normal oil from WM and near the same as Walmart Pennzoil Full Synthetic. In a crunch, I would use the Pennzoil as I used it for a long period on my old 2 stroke. That motor was under powered for the boat for my liking and she was always running offshore for more that 1.5 hours each way at 4500 to 5000 rpm's and never missed a beat!
Happy now I have sufficient power with the twin 200 HPDI's, but due to running with lower RPM's, I feel the additives will help keep the carbon down.