My opinionated review
I feel like the Nexus 4 and Iphone are good at different things. The hardware on the Nexus 4 beats the iPhone hands down and I rather like the look of it more so than the iPhone. The camera on the front is 13 mega pixel compared to the iPhone's 12 megapixel. The glass might break easily even though it is gorilla glass too and that's where the iPhone is better. The battery life on the iPhone is almost 1.5 times greater than the Nexus 4 but it is able to get through the day (which is fine for me). You can't extend the storage space on either phone which sucks but the iPhone can go up to 64 GB which is great and Nexus can only get to 16 GB. The plus that Nexus has is the google play music where you can store music online over 20,000 songs which can take up to 60 GB on the Nexus 4.
The size of the Nexus is also a lot larger. Well not a lot but the width and height are larger. The height may be larger but the on screen buttons make it as big as the iPhone. You are able to remove it with some applications and the buttons also dissapear in some videos like ones you play on youtube. The width though is a considerably larger and is better than the iPhone. The iPhone's color is also more saturated which some people may like but the Nexus 4 is less saturated and is known to bring out the real colors of a photo.
The software of android has been improved a lot with the google's butter project and with the Snapdragon, it feels great. The ability to customize it any way you please is a great plus for the android and I love that. The iPhone has the same old format and has no way to customize it. The siri that was one of the iPhone's greatest achivements is now being faced up against the google now which is almost as good. The Nexus 4 is faster than the iPhone in a lot of things but I'm not sure but the games are optimized for iOS, not android and some games perform slower. One noticeable one is Asphalt 7 which is somewhat slower and the graphics are a tad worse. One huge plus for the iPhone is that a lot of people use it. That means more applications in the market and you can play with your friends across devices but that's not a serious issue, all the big games are ported to Android so you won't miss out that much
Verdict: I like the Nexus 4, it's my opinion but I can see what people would go the iPhone. The price of the iPhone is a deal breaker, 700 is too expensive for a non contract and the Nexus 4 only being half of that. Too bad the Nexus 4 has been sold out forever so not a lot can have it