Seems to me my newest bottle of Optimum Compound is a bit stronger than the first few bottles I had (purchased when it first became available). While detailing a car today my OC was getting low so I grabbed for the new bottle I purchased recently and immediately noticed increased compounding swirls (applied via rotary). I can't say that I noticed increase defect removal, as I had already wet sanded and heavy compounded twice (aftermarket paint). I'm thinking maybe David decided to sneak in a few more abrasives (a good idea if he did) after many people were finding almost no difference between the polish and original compound. Today, after the OC I followed with OP...and even though I used the same type of pad, there was a large difference. I'm not even sure they would admit to tweaking the formula, but I can say that my two bottles are not the same (thankfully).