Which should you choose? The following specs are below for each phone. Your choice will depend much on what you find is important to you, do you want good pictures? Do you want to watch movies? Play games? Use it for business?
Lets have a look at the individual phones.
Samsung Galaxy S6 Tech specs
Capacity
32GB | 64GB | 128GB
Dimensions
143.4 x 70.5 x 6.8mm
Colours
Sapphire Black, Pearl White, Platinum Gold
Display
5.1" Super AMOLED display with Quad HD resolution
2560x1440 Quad HD
577ppi
Operating System
Android 5 Lollipop
Camera
16 megapixels
Dual LED Flash
5MP front facing camera
Video recording
4K video recording
Processor and memory
Octa core
Quad 2.1GHz + Quad 1.5Gh
Samsung Exynos 7420
3GB RAM
32GB/64GB/128GB internal phone memory
Mobile and wireless
Quad band GSM: 850, 900, 1800, 1900 MHz
Quad Band 3G: 850, 900, 1900, 2100 MHz
LTE CAT 6: 700, 800, 850, 900, 1700/2100, 1800, 1900, 2100, 2600 MHz
Wi-Fi (802.11 a/b/g/n/ac (2.4/5GHz), HT80 MIMO(2x2) 620Mbps)
Bluetooth 4.0
GPS and GLONASS
Internet data connection
3G
4G
Works in USA
Speakerphone
Voice dialling
Voice recognition
NFC
USB 2.0
Wireless charging
Sim card
Nano-SIM
Battery size
2,550mAh
iPhone 6s tech specs
Display
4.7-inch Retina HD display
Resolution
1334x750 pixel resolution at 326 ppi
Storage
16GB, 64GB, or 128GB1
Mobile and Wireless
GSM/EDGE; UMTS/HSPA+/DC-HSDPA; CDMA EV-DO Rev. A; 4G LTE Advanced up to 150Mbps
Wi-Fi with MINO (802.11 a/b/g/n/ac)
Bluetooth 4.2
GPS
GPS and GLONASS
Camera
New 12-megapixel iSight camera with 1.22ยต pixels
Touch ID
Fingerprint sensor built into the Home button
Battery
Built-in rechargeable lithium-ion battery2
Talk Time
Up to 14 hours on 3G2
Standby Time
Up to 10 days (250 hours)
So which to choose based on specs?
Both phones are excellent choices, however, we would recommend the Samsung over the iPhone in this specific comparison. They are both expensive phones but what you get is more of a mini computer their an actual phone. You may see it as a computer with the ability to also make calls. It is a tool which will give you much enjoyment and help you with the daily tasks. Enjoy your new phone!