I agree with Gary 100% with all his comments. I also have the SKF bearings and will never look back. Never had an axle slide when racing and Changing axles is so much quicker and easier and my axles are super smooth because there are no set screws to file and the axle spins freely so much better.
Last year in the heat I always had an issue where the kart would bind up in the heat and the rear would have a lot of grip. This year however we have not had that issue at all. Don’t know if it is due to the SKF bearings rolling more free or not but last year we had regular bearings in and this year we went with the SKF Ceramics and we don’t seem to have that issue.
I have been very happy and like Gary said I will never look back either. I know they are pricey but for me I would find a way as I like them that much.