Am here to help you make tell you the difference between iPhone 6 plus and Galaxy S5
OS: The iPhone 6 Plus uses iOS (8.x) upgradable to iOS 8.1.3 while the Samsung Galaxy S5 runs on Android 4.4.2 KitKat that can be upgraded to Android 5.0.
DIMENSIONS: The iPhone 6 Plus has a dimension of 6.22 x 3.06 x 0.28 inches while its competitor the Galaxy S5 has a dimension of 5.59 x 2.85 x 0.32 inches.
WEIGHT: The iPhone weighs 6.07 Oz while the S5 weighs 5.11 Oz, it’s obvious that the Samsung smartphone weighs less than the iPhone 6 Plus.
RUGGEDNESS: The iPhone 6 Plus does not have the capability to resist water or dust whereas the Samsung Galaxy is water resistant (but for a short time, not for hours), and dust resistant.
SIZE: The iPhone 6 Plus is actually blessed with a 5.5 inches while the S5 comes with a 5.1 inch screen. The difference in screen is not actually much.
The iPhone 6 plus has a screen resolution of 1080 x 1920 pixels, while the S5 also have a resolution of 1080 x 1920 pixels. The pixel density of the iPhone is 401 ppi, while that of the S5 is 432 ppi.
SCREEN DISPLAY: The iPhone 6 plus uses a Retina HD kind of screen while that of the Samsung galaxy is super AMOLED.
CAMERA: The iPhone has a rear camera quality of 8 megapixels and a front camera quality of 1.2 megapixels while the S5 uses a 16 megapixels rear camera and a 2.1 front camera quality.
BLUETOOTH VERSION: They both make use of the Bluetooth 4.0 feature.
EXTRA FEATURES: The Galaxy S5 and the iPhone 6 Plus both have video calling, autofocus, video sharing and face detection.
BATTERY CAPACITY: The iPhone 6 plus has a battery of 2915 mAh, while the Samsung Galaxy S5 comes with a 2800 mAh battery.
After all said and done, if you ask me for my overall opinion, I will say it's 50 - 50.