I think biowheels are excellent for seeding new tanks, but otherwise once a tank is established you can toss them in the trash because there is plenty of biofilm all over the tank and filter - they are not necessary. I leave them floating in the back of my bigger tanks and use them to help a cycle when setting up a new tank.
I like the idea of a large canister and a HOB
combination for bigger tanks. You have flexibility that way. I would not choose one filter over the other based on biowheels, though. AC
's are probably the most popular power filters among advanced aquarists, if you were to take a poll. There is good reason for that, but tons of people love their Penguins and Emperors, too. Personal preference.
Glad that Eheim finally got itself together! I'll bet it heard some of your threats and decided to get to work