Less obvious comparison between the HTC One M8 and Samsung Galaxy S5

*Work in progress*

Obvious comparison

Similarities
Very similar hardware and run the same version of Android (currently 4.4.2 as of August 23, 2014).
Both have the 801 snapdragon quad-core processor (though Samsung's is 2.5 GHz,  2.3 on HTC One).
Both have 2 GB of RAM

HTC One 5" 1920x1080 screen
S5 5.1" Super AMOLED 1920x1080 screen

Both have a power button and volume rocker, no buttons dedicated to opening a camera or fitness app like some competitors. Less to break I guess.

General differences
Samsung Galaxy S5
water resistant
replaceable battery

about 2 mm wider
about 1 mm thicker
about 4 mm shorter

I have large hands, and I prefer the slightly smaller width of the HTC One, but I don't like how the power button is at the top of the screen, and even my fingers have to reach to press it. Although, you can, in theory, just swipe the screen of the HTC One and it will turn the screen on, launch to the dialer, etc. though in my experience it can take several swipes, which is annoying for me.




Less Obvious Comparison

HTC One
Visually looks and feels more "classy" and "posh".

Practically, I didn't last more than 10 hours before dropping it. If I kept this phone, I would have to have a case for it on day 1. As a second user, the phone came to me with chips out of the aluminum. It is super slick and could have easily slid out of my pocket, and did slide out of my hands. I feel the personal need for a case on both which brings them to a similar playing field, but I would gravitate to the metal feel and look initialy, but after dropping it, I think the plastic is more my style, though the S5 can et the bezel damaged too, also looking not so great.

I have a huge hand, and my index finger has to stretch to reach the power button on the top of the phone. Samsung's side mounted power button feels more natural, but the side butto the S2 and S3 is known to stick causing the phone to turn itself off until cleaned by a professional, or, sometimes a new motherboard (generally meaning phone) is needed, which is a nasty design flaw in my opinion. I had that power button issue in three of the five  S3s and one of three S2s I and my sister went through in the past 2-3 years.

The HTC One can enable a feature to use a wireless network for texting and calling, intended for use in buildings where cell signal is poor. I didn't see this option for the S5.

Samsung S5


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plastic case with a dimpled back and a grippy backing. If you don't want to use a phone case, the S5 is less likely to slip out of your hands and pocket compared to the sleek (slippery) aluminum HTC One M8. Within the first 10 hours of use without a phone case, I dropped the M8. The plastic silver bezel of the S5 will get chipped and dented, but the back is pretty forgiving, thought he white back can get a little dirtly looing after extended use. The M8 metal will show crumpled metal if dropped and nicks will show on the back and sides after while.

ip76 certified. Waterproof.

The screen adapts to what you are doing for best viewing.

Camera fast autofocus, 16 MP, low light, it isn't the best. DOes have selective focus options if you select it before snapping. Has picture stabilization, which can take several seconds to shoot. 1080p and 4k video.

Less bloatware than the S3 and S4.
Air View.
My Magazine
Samsung Smart Switch makes it easy to transfer things from your old phone, both iPhone and Android.
S Health App w Heart Rate, food and exersise tracking
Fingerprint sensor 
Download Booster which can use WiFia dn 4G speeds
Battery 14 hours
Ultra power Saving more, limits apps, 30% battery life

HTC One
Fits well in the hand due to the curve, though a tad tall.
Less lag than others.
4.1 UltraPixel, focus post snap without selecting an optin for doing so before the picture like on the S5. Dedicated depth sensor. 5 MP front camera, though i didn't notice it being any clearer than the 2 MP front camera on the S5.
Not as much detail as the S5 in good light. Maybe a little better in low light.
3D is cool gimmick.
Automatically creates a montage of pictures, which can be confusing at first because it looks like a picture in your gallery.
Presents news that you will likely find interesting.
Blinkfeed
Speakers are 25% louder than the M7

Build/aestheitics/durability


Battery life and charging time
S5 2800 mAh removable battery
~4.5 hours to charge on Micro USB
~2.5 hours to charge with USB 3.0 with included wall charger
With mostly a lot of web browsing I usually get 14 hours, longer if I am not on it and kill apps.
On Ultra Saver Mode, I held 6% for an hour.
Greyscale option, though in my limited tests, there dissapointingly wasn't a notable difference.
It's easy to adjust the screen brightness, a major power drain, by pulling down the menu from the top

S5
2600mAh captive battery
~4.75 hours to charge with Micro USB (No USB 3.0)





Camera

List of modern smartphones with a removable battery

Not many phones have removable batteries anymore, but it looks like LG finally realized that people don't want to carry a large external battery pack with them. Here are some smartphones from 2012ish and newer with removable batteries.

Sprint

HTC Evo
HTC Evo 3D
HTC Evo LTE (comparable to the Samsung S3)

Samsung Galaxy S2-Released 2011 (Dual core)
Samsung Galaxy S3-2012 (dual core in US)
Samsung Galaxy S4-2013
Samsung Galaxy S5 (and active/sport models) 2014

LG G2X (P999) -Released 2012 (dual core) (Not the G2)
LG G3 -2014

Additional phones by AT&T

Samsung Rugby