The Aqueon seems like a neat way to polish the water after filtering through the canister. I think the Oase is different in that you can remove a tube which contains the prefilter sponges without having to disconnect and clean anything else. I have done this once since I set it up a month ago and it was super easy and totally clean!
Can you send a pix of the hose connected and the rim connectors? Those have been my big issues and they never show them in the ads. Can you use other floss in the HOB unit instead of the carbon? What is the size of the HOB unit?
I don't know what you mean by rim connectors, you mean the hose connectors? I just took pics of everything, hopefully they will help you out. The only thing I don't like is the intake is long. I have a 20" high so it isn't a problem. It extends too, so if you have deeper its good for that. I was hoping to have one intake low and one high in the water column (like a skimmer), but that would require some customizing.
One other note, the 400GPH model comes with a Y for the outflow and 2 HOB units. So with that one you can run both HOBs or any mix of the three outflow choices they provide. I went with (2) 200GPH models to have some fault tolerance and be able to keep one running while I maintain the other. It also allows a lot of variety for bio media.
Here are the hose connects to the filter. I have not used a canister before so was absolutely astounded at the room inside to put media!
Don't know why this image shows up sideways. Here is the connection on the one HOB I am running.
Inside of my running HOB
These are the other outflow options you get
Bottom of the HOB/hookups
Inside of the HOB. You could easily DIY the inserts. It helps that it has that little blue cage to mount them in.
The filter chamber is pretty good size if you wanted to do something with it. It's slim HOB but there is enough space. For sizing, the insert refills are their large size (same inserts used on their HOB filters)
Hope it helps.