Google's Nexus 5 is out in the Indian market. While intense discussions about its comparisons with other rival brands are going on, we take this chance to analyze its worth against the predecessor, Nexus 4. Since Google is still continuing with the predecessor, the comparison becomes pretty obvious. Here it is for you- 
Display- Nexus 5 comes with a 4.95-inch (1080 x 1920 pixels) 445 ppi full true HD IPS capacitive touchscreen as compared to the 4.7-inch WXGA IPS HD (1280x768p), 318 ppi display. While the former has Corning Gorilla Glass 3 protection, the later has Corning Gorilla Glass 2 protection. Hence, its a big leap in terms of display.
Processor, Chipset and RAM- Nexus 5 has 2.3 GHz quad-core Snapdragon 800 processor with 2GB RAM while the predecessor ran on 1.5GHz Snapdragon S4 Pro quad-core processor with 2GB RAM. So, you will surely get significantly better processing experience on the new device as the Snapdragon 800 is the best unit currently.
Memory- 16 and 32 GB internal memory variant come with the new launch while the older one had 8 and 16 GB variants. Both devices have no card slot. Since the newer one offers a bigger memory option, I think this one should go to the Nexus 5.
Operating System- Nexus 5 runs on Android Kitkat 4.4 platform with many new features. Nexus 4 has been updated v4.3 Jelly Bean platform. However, the Kitkat 4.4 will soon be available to Nexus 4 users. 
Camera- Both devices have similar 8 MP primary camera and 1.3 MP front camera with features like autofocus, LED flash, Geo-tagging, touch focus, face detection, photo sphere etc. However, the new generation comes with Optical Image Stabilizations) and HDR+ (High Dynamic Range) for better picture quality. The camera is a big up from the previous generation.
Connectivity- Both the devices offer connectivity options like 3G, GPS, Wi-Fi, Bluetooth, NFC, WLAN and USB. However the Nexus 5 comes with LTE support which might be beneficial in future.
Battery- Nexus 5 has Non-removable 2300 mAh battery to give 200 hours of standby and 17 hours of talktime on 2G while on Nexus 4, you will have 2100 mAh battery rated for upwards of 15.3 hours of talk time. Price- For 16 GB variant of Nexus 5, you pay Rs 28,999 whereas the Nexus 4 is selling for around Rs 22,000 for the 16GB variant. You also get the option of a 32GB variant on the Nexus 5 which will set you back by Rs 32,999.
Verdict- Nexus 5 is a significant over Nexus 4 on all counts and is more than worth the price difference. Moreover, this leap comes at no substantial cost escalation. In short, a green light from my side.
