I dunno, I have a mastercraft rotary tool in the bin, my newest one only works at certain speeds, the cheapo I bought for $13 from princess auto has been working fine for about 4 yrs now, outlived 3 big name ones...
I buy alot of name brand tools for my detailing stuff, but some of the things I get at princess auto lasts just as long as my other stuff at a fraction of the cost. it all depends on the tool and mfg... I'd never buy any buffer other than a makita, had cheaper ones but they don't even compare, not close. 4 yrs now and the makita still works fine.