If you are thinking about it you must go for the 6S.
I have been using Nillkin Nature the last years and I'm very satisfied.
I bought one and the battery was still terrible. I ended up selling the phone. Probably will wait to see what the s7 has to offer. The s4, s5 and s6 were disappointing phones.
S5 battery was great. I don't agree....
Very interesting. I didn't knew anything about this.
I also got an error trying to update the firm.