My unicomp goes as high as 8KRO, but it's not for gaming, as some critical key combinations more than 3 keys fail.
Do you man it's "s high as" 8 key rollover, or that usually it's about 2-3, and for rare occasions it's 8. The reason I ask is because getting a membrane keyboard to be more than 2KRO is really difficult. You need variable resistance traces (or whatever the sidewinder uses) or a flexible PCB and diodes (I want to try this sometime) or some other crazy solution.