I have a magnum 350 canister and an eheim canister and a AC 500 on my freshey tank. The AC moves lots of water and it is very easy to clean. I like it a lot.
The mag 350 is a great filter. I run it with floss and the carbon basket 98% of the time. You can also run the micron filter for some water polishing and I have heard some have used it as a diatom filter but I haven't yet. On this filter the pump is on the bottom so it doesn't need priming just fill it with water and plug it in
I would buy this filter again.
The eheim is a little tricky to get running again and I did get rid of the eheim noodles and rocks and I replaced it with bio balls and a few sponges and is running great. But I would buy the mag 350 over the eheim.