I have been using my all-Stainless 3one6 ~80% of the time and really like it. It is a lot more aggressive in terms of shave efficiency than my EJ DE89 and Gillette Tech (and similar razors) and is much less aggressive than my Muhle R41 while being almost as efficient shaving.
The Muhle Rocca is slightly more aggressive but, not enough to notice unless you have both in hand for the same shave. The 3one6 is more user-friendly in terms of washing out the shave soap and whiskers during the shave. The open safety bar also seems to let more lather in for cushioning while shaving. This isn't to say the Muhle Rocca is better or worse, just that it is very similar in shave quality with some differences that could make it slightly better or worse depending on the individual using them.