I dont know if you are the one paying the power bill each month but looking from a electricity usage standpoint I would go with the koralias. Also with the Koralias you get more flow and imo
better flow than a maxi jet. Just to give you an idea to run 2 maxi Jets for a month it costs a little over $5 while two Koralia 3's would cost you around $2.50 a month and you get 3X the flow. So the extra money you spend on the Koralia's is made up for through your energy bill.
In the long run the Maxi will cost you more, in electricity and live stock (snails and other animals tend to get sucked into them and cant get off.)
Just my $0.02. sorry if its alittle jumbled, im tired haha.