Samsung designers used to put practicality above all and even tried to appease those who didn't like the plastic look with faux leather designs. That didn't work out so the Galaxy S6 brings the favorite combo of the corporate world - metal and glass. Such designs have been around for years so it's not very innovative, but there's a reason the combo has stuck around for so long.
LG isn't treading new ground with the leather back either, but Motorola's former laser focus on the US means the Moto X is still quite rare. LG's design with the back buttons was already recognizable, but the company added a decorative stitching and a slight curve to the phone's body to make it truly unique.
Note that while we keep mentioning the leather back it's only an option - and an expensive one at that. By default the LG G4 comes with a plastic back, which isn't nearly as nice. Actually, we prefer G3's brushed metal-effect plastic. The Samsung is more consistent in this regard, your only worry is availability of the color you picked.
The Galaxy S6 has an optional extra in a way too, the double-curved screen of the Galaxy S6 edge. Unlike the gentle arc of the G4, the sides of the S6 edge screen slope off to offer both a unique look and additional functionality. You pay the early adopter fee for that one though.
Despite the tangible 0.4" difference in screen size, the two phones aren't that different in size. The Galaxy S6 measures 143.4 x 70.5 x 6.8mm and weighs 138g, while the LG G4 is 148.9 x 76.1 x 9.8mm and weighs 155g.
The extra width on the G4 will affect handling, if you have smaller hands you may find it difficult to hold the phone and use it with one hand. The thickness adds to the bulk as well, while the slight curve makes it seem even thicker.
The Galaxy S6 is not the most compact device possible either, but the lower screen bezel holds the fingerprint reader (aka hardware Home key) and the capacitive Back and App switcher keys. The LG uses on-screen keys, which leave the lower bezel empty and eat into the screen real estate.
If you have used a 5" phone before you shouldn't have issues with either of these. The LG G4 curved, rounded back fits well in the hand. The curve also makes it hug your leg more easily if you keep it in your pants' pocket.
The Galaxy S6 sits well in the hand too, the front and back glass panels have beveled edges, as does the aluminum rim. This makes side-swiping gestures smooth and make for a sleek in-hand feel. However, the flat, smooth glass on the back doesn't offer much grip. Neither does the aluminum for that matter.
The curve of the LG G4 is so slight it may be hard to see unless you have something straight to compare it against. So its impact on usability is fairly small, but it's there reaching for the top and bottom edges of the screen is just a bit easier because the screen curves forward to meet your finger.
Both phones have capable selfie cameras above the screen, both with 4:3 sensors (despite the widescreen main cameras). The LG G4 brings 8MP with 1080p video, while the Galaxy S5 is down on still resolution - 5MP - but wins on video resolution - 1440p (aka QHD).
Around the back are the impressive 16MP main cameras of both phones. We'll cover them in detail in a later chapter, for now we'll just point out the hardware differences. The thin Galaxy S6 has a protruding camera, that doesn't really add to the bulk, but you need to be careful with it. Next to the camera is LED flash and the heart rate sensor.
The LG G4 camera also protrudes slightly, despite its thicker body. It also comes with a single-LED flash as the second LED that was on the G3 has been replaced by the Color Spectrum Sensor. The G4 camera carries over the IR emitters for the Laser autofocus.
Also here are the only three hardware buttons on the LG G4. They are placed on the centerline of the phone, just below the camera. Some find this positioning more natural as their index finger lies right on the buttons when they hold the phone. Depending on your grip they may be a bit hard to reach though.
The Galaxy S6 sticks to the classics - the Power button on one side, the volume controls (this time separate buttons) on the other. They are easy to reach and the volume buttons can be used as a hardware shutter key for the camera (this isn't very comfortable with the G4 buttons).
Both phones have IR blasters on top, used to control TVs and other AV equipment, air conditioners even.
Neither company went for stereo speakers, though both companies have plenty to say about how loud they've made their sole speakers. We'll check those claims later, but note the positioning. The Galaxy S6 places its speaker on the bottom (so it doesn't get muffled as easily). The LG G4 speaker is on the back, but the curved design gives it a bit of breathing room.
Samsung caused a big upset when it permanently affixed the back cover, which means you can't access the battery. The company also dropped the microSD card slot, citing the performance hit users may experience with cheap cards.
LG stuck to its guns though and is now one of few companies that give you access to the battery and let you expand your storage at your leisure.
Samsung does offer wireless charging though, supporting both Qi and PMA standards. This makes it more likely that you'll find a venue - restaurant, airport or something else - that offer your brand of wireless charging. The LG G4 can gain Qi charging capabilities too with the right back cover.
Winner: Tie. Samsung went back to the drawing board and produced its best-looking design yet. The Galaxy S6 is a very attractive phone made of quality materials, thin too if that's your thing. The sealed battery and no memory expansion are deal-breakers for some though.
The LG G4 - if you get the optional leather back - can look very upscale too. It may be a bit too large for some, it's certainly thicker than it needed to be. The curve doesn't add much to usability. Even if the leather back gets scuffed, you can easily replace it, battery and memory card too.