Remember what we learned, that the strength may be stronger for now, but it can change from batch to batch. The splitter idea will be your best bet for when your pills are stronger than usual and a whole pill may be necessary when you get a weaker batch. Maybe you wont ever get a weaker batch, hopefully.
After reading the very informative thread on "brand vs. generics" I switched my oxycodone too, I switched to a different generic Amide, instead of the Mallincradt, and found a difference, but not as much as you found with your switch so I most likely will see if I can afford a switch to brand next, so that hopefully I can cut back on my dosage. The strange thing I found when calling the different chain pharmacies I have to go to due to having state aid, was that all six of them only carry Mallincradt. The chain pharmacies told me they are regulated by their "main office buyers" and couldn't order anything different? Anyway, I found the one that carried the Amide and went with that. I felt it not right that all those pharmacies carried the cheapest "crappy" brand only, I think that is what is called "having a monopoly on the market". One of the largest popular pharmacies didn't even have the main "brand" on hand, what do they think everyone wants generic? and then to only offer Mallincradt, I think that's what's crappy!