I have the Emperor 280...also another that doesn't work...they are notorious for empellor troubles, but you can buy the replacements. I used the Emperor for 6 years on my 35 gallon Hex and now use it on my 75 just for the "wave" action and filtering new sand particles out with floss in it. They have a neat "Super Cartridge" you can get cheap that is big and you can fill it with LR
rubble . I did that and it worked great..I removed the bio-wheel first.
On the other hand...I found an AquaClear that was in my shed a while back..it had been there for over 15 years...it fired right up!!!!
I personally, like the Emperor as it is a really sturdy filter.