Think its like most everything else. Buy a big name brand of most anything, you're paying for the name more so than the product itself. I find unknown name brands work and/or last just as long as the big name items and maybe even longer. Also when buying items whether to buy the "best", "middle best" or "normal", I'll buy the middle best cause even the best can break down as the other 2 classes can.
Just as an example, a friend went to buy a new boiler for his furnace and was told not to go with the highest rating but the next one below it for reasons they found issues with the high rating one. He saved money, still gets a good rating boiler and his power bills are as good as if he bought the high rating one. Plus he has less headaches knowing that the one he did buy works as it should with fewer hiccups.