I can tell you that the materials of the two 3M masks are vastly different. The fit virtually is the same. In fact, the N95 has a slightly better fit as it doesn't use those faulty red rubber bands that the FFP3 does - it has a tighter pull by using a woven elastic cord instead.

There are two spots for leakage - the nose fit and the neck, but both do a great job and come with a tab for the neck so that you can adjust if it gets loose.