I have used Black & decker for many years , I now own & use a Makita & Dewalt .
I like the makita as its a tad lighter then the dewalt , and I like the crossover handle on my model , instead of just a handle attached to the left side of the buffer , even though its interchangeable to the right .

Both have nice speed variances .
The Makita and dewalt are fairly easy to work on if they need brushes , or cord repair .

Just make sure it has some heft , but not real heavy body , because if you use it for any length of time it will get to your arms and hands .

Have not used any of the others .