Nexus 10 iPad 4
Network Wi-Fi Wi-Fi, GSM, CDMA
Operating System Android 4.2 iOS 6
Processor ARM A15, Mali T604 Apple A6X
RAM 2GB 1GB
Storage 16GB/32GB 16GB/32GB/64GB
Camera Rear 5mp, 1080p 5mp, 1080p
Camera Front 1.9mp 1.2mp, 720p
WiFi 802.11a/b/g/n 802.11a/b/g/n dual-band
Nexus 10 cost about £319 (16GB model) and £389 (32GB model). While, iPad 4 cost about £399 (16GB model) and £479 (32GB model). So price wise Nexus 10 is cheaper by £80-£90 than iPad 4.
Nexus 10 has a larger RAM capacity than iPad 4 which makes Nexus a bit fastes. Nexus 10 has a more recent operating than iPad 4 but it seems that iOS 6 has more secure. Apple A6X is faster than ARM A15, Mali T604.