As a user of the Samsung Gear fit.. I think you would be good with Fit2

Tho you must be deep into Samsung's eco system. (S Health)
I've already started using Samsung health 2 weeks ago and it's far more intuitive and pro-active than FitBit. It's tracking via phone but I need a tracker for my boxing and running as I do not have my phone on me when I do.
One thing Samsung Health lacks is the integration into myfitness pal for minusing calories from activities which I have been using heavily but it's not a big deal breaker moving away from Fitbit cause I feel they do not work on updates and solutions as fast as Samsung. The interface is actually about the same as Fitbit so it was really easy to setup and use.
Other thing is that not many people are on Samsung Health for benching your progress with others which is understandable since not many actually use Samsung Health. I'm definitely getting the Fit 2 Pro as it seems a great replacement based on my usage.
I also hope Samsung starts incorporating VO2 max functionality on their fitness trackers as its an in thing now and I'm sure they can pull it off.