any filter that is backed up with a warranty that you can rely on claiming is ok...
the other thing you want to looking out for is the availability of spare parts. one of my fluvals came with a broken ceramic shaft, and as you know it took me a whole 2 seconds to get a replacement. I see value in that.
build quality is another thing.... weak links, pipes, seals, clamps that keep the filter shut - should all the taken into consideration.
think of how long the warranty lasts for - can you get help after it runs out?
you're better off buying 1 filter that costs twice as more than another that leaks, dies, causes you trouble, and worst case scenario leaks.
if the filter is going to be in a common area of the house like the lounge - you may look at getting the quietest filter for that price range - not compromising on performance though.
what i look at when buying a filter is simple. lets assume any and every filter you buy is going to die out on you. how easy is it going to be for you to get another one at no cost, and with minimal delay. when you narrow your options based on that - choose any one that you want, and you wont go wrong.
HTH! :bounce: