A couple of months ago, I did both : went over the top heading South (most of the way, anyway, until we had O2 failure but that's another story!) and came back northwards at lower level.
You can get through from lake Maggiore to Zurich, but - and I mean BUT - I've done it, and frankly I wouldn't want to have to do it again. The weather closed in on me, we had serious problems with both radio and GPS reception, and I can honestly say it's the most breathtakingly beautiful and breathtakingly frightening place I have ever flown in.
If you're going to do it, I seriously advise you to get some advice from local flyers who are used to it, and stick to it rigidly - no matter how good a pilot you are.
FF
