Reasons to buy iPhone 4S:
- Dual-core processor and 7x more powerful Graphic
- Siri natural language commands and dictation engine
- 8MP camera with improved low-light performance and capture speed
- 1080p video capture with stabilization
- GSM/CDMA dual-mode device
- Dual Antenna
- 16GB,32GB,64GB
- Bluetooth 4.0
Reasons to stay with iPhone 4:
- Same design
- Same Retina Display screen & same size
- The amount of RAM doesn't improve
- Siri doesn't work too well for people outside the US
- You'll manage to snap more photos and longer videos and avoid 1080p playback problems
