yaya,
Not neccessarily Use Brand A sterilizer must use Brand A bottles. However, the same brand they customized the design to suit the same brand bottles. Like Avent sterilizer, the trays are all fit-fit to Avent bottles size. So you dun need to spend so much time arranging the bottles. They specially design the teats to put where, bottles put where, screw cap put where. But if you use other brands bottles, you can just take out the trays and dump everything inside the sterilizer lo..
I would say, if use same brand, it will be more convenient !