It's all down to personal opinion and preference. It's not just as simple as the m8 "having better speakers and materials."If people are saying both this and m8 are great could go for either etc... Then why wouldn't you go for the better speakers and materials on the m8? Unless this phone under cuts the m8 you are just buying an uglier phone for no reason? :/
Why would people go for the s5? a lot of people prefer SAMOLED screens and think they are the best screens in the business. You could also say the s5 has a better camera, is waterproof and dustproof, swappable battery, fingerprint scanner, it is lighter and slimmer. Believe it or not some people even prefer touchwiz or a plastic build! Maybe people want a phone that is compatible with a Galaxy Gear. Also brand name means a lot and some people would always prefer a Samsung phone over an HTC phone, just by brand name alone.
I'm probably sounding like an s5 fanboy right now

Personally I'll be waiting for either the LG G3 or Note 4
