I actually find the outdoor visibility of the M8 screen better - but not by a big margin.
To me I think its the performance thing - you use your camera 5-10% of the time - but performance of your handset is overriding and effects you 100% of the time no matter what you are doing, and thats where the S5 / M8 difference is more appreciable than anything else.
The S5 isn't a slouch, but those little hiccups and the memory management are annoying.
Neither is perfect to be honest, and if you can handle the size of the 1+1 it certainly stands head and shoulders with them .....
Yeah, the disappointing performance of the SGS5 is one of the reasons why I didn't even consider that phone to replace my SGS3.
I liked the M8 on paper, but when I tried it on the store I just didn't feel any "excitement". Don't really know why, but I didn't felt anything towards that phone.
But I agree 100% that the performance of the SGS5 is not on par with the rest of the flagships. To me it's because of TouchWiz.
After 2 years with the SGS3 I didn't want another Samsung phone, especially considering I dislike the build quality of the SGS5.
I use the camera a lot, mainly for video recording, so that's an important point for me.
Also, I don't like AMOLED screens. I'm am IPS guy, but the Super LCD screen of the M8 didn't wow me like the one in the Nexus 5, LG G2, etc.
Still, between the two, I would go with the SGS5, just because of my brief experience on the store with the M8, where I wasn't impressed.
Sorry for the off-topic guys.