In most ways, not at all but then there are some major hangups that I read about pretty often. The biggest, most frequent is easy to see how it happens but also easy to avoid. It makes restarts after cleaning easier to do if the tubing is run without leaving droops in them where water can collect. That can make getting the canister filled right after cleaning real headache. Just run the tubing more or less in a upslope all the way so that water runs down and air goes up and out. Doesn't have to be straight but just not up/down like a roller coaster?
Then the second problem seems to be the directions on HOW to turn the nuts tight on the canister and cutoffs. They turn opposite than most screw/bolts we tighten. Turn them clockwise to move the nut fully down on the fitting, then push the tubing on and turn the nuts opposite of normal to tighten them to hold the tubing. Simple if you are not the normal mechanic type that knows which way to turn things to tighten them!! But if you are a guy that's used to doing it all the time, it just seems wrong and the directions are not clear on that.
I would not expect you to have much trouble once you get past those and do a good read of the directions. One thing people complain about is that the directions come ina more different languages that I even knew about. That makes them seem really difficult just because there are so many sections to ignore to get to the one we can read.
One way to spend a bit of time and get to know the filter is reading the online manual. Harder than having the filter in front of you but you can get a feel for what things should do?
Manual here?
Eheim Classic External Canister Filter
Check page three item "G" for the tubing and nuts I described? It's all drawings and some miss the fine points of which way to turn the nuts.
There are also lots of U-tube videos but then I never really trust those as you don't really know how the guy operates. He may be an expert or he may only just have a new camera!