I would tend to say that device approval is easier in the EU because it is faster. And it is faster because it is simpler and is based on a checklist that leaves little room for gray area and saves time by eliminating the need for further discussion. Furthermore, the EU requires that clinical safety be proven (for Class IIa, IIb, & III devices) with clinical evidence (which may or may not be a clinical trial) while the FDA requires a clinical trial itself, which can take years to complete.
This table from an article on Science Direct nicely lays out a comparison of the two approval processes:
http://ars.els-cdn.com/content/image/1-s2.0-S2452302X16300638-gr2.jpg

Original Article:
http://www.sciencedirect.com/science/article/pii/S2452302X16300638