Sony
Sony Xperia X

Samsung
Samsung Z2

Features
Android OS, v6.0.1 (Marshmallow), planned upgrade to v7.0 (Nougat), Yes, Accelerometer, proximity, compass, Yes, Octa-core (4x2.0 GHz Cortex-A53 & 4x1.0 GHz Cortex-A53), Mediatek MT6755 Helio P10, Mali-T860MP2, Yes, with A-GPS, GLONASS, Yes, SMS (threaded view), MMS, Email, IM, Push Email
Compass, Fingerprint (side-mounted), barometer, proximity, gyro, Accelerometer, Qualcomm MSM8956 Snapdragon 650, Yes
Accelerometer, Spreadtrum SC9830
Memory
microSD, up to 256 GB (dedicated slot), 16 GB , 2 GB RAM
microSDXC (uses shared SIM slot) - dual SIM model only, up to 256 GB (hybrid slot), MicroSD, 32/64GB, 3 GB RAM
MicroSD, up to 128GB, 8 GB, 1 GB RAM
Display
IPS LCD capacitive touchscreen, 5.0 inches, 720 x 1280 pixels (~294 ppi pixel density), 16 M colors
Scratch-resistant glass, oleophobic coating
Triluminos display
X-Reality Engine, 1080 x 1920 Pixels, 16:9 ratio (~441 ppi density), IPS LCD capacitive touchscreen, 5.0 Inches, 68.9 cm2 (~69.8% screen-to-body ratio), 16 M colors
TFT capacitive touchscreen, 4.0 inches, 480 x 800 pixels (~233 ppi pixel density), 256 K colors
Battery
Up to 11 h 20 min (2G) / Up to 10 h (3G), Charging 10W
Pump Express+ 2.0, Up to 560 h (2G) / Up to 603 h (3G), Up to 55 h, Li-Ion 2300 mAh, non-removable
Fast charging 18W
Quick Charge 2.0, Li-Ion 2620 mAh, non-removable
Li-Ion 1500 mAh, removable
Selfie Camera
HDR, 8 MP, f/2.0, 1/4", AF, 1080p@30fps
1/3", 22mm (wide), 13 MP, f/2.0, 1080p@30fps
VGA, f/2.4
Main Camera
1080p@30fps, LED flash, HDR, panorama, 13 MP, f/2.0, 1/3.1", 1.12µm, PDAF
1080p@60fps, 1080p@30fps, HDR, Panorama, LED flash, f/2.0, 1/2.3", 23 MP, 24mm (wide), PDAF
720p@30fps, LED flash, 5 MP, f/2.2