Advantages for Android
I think that liberty should be the first consideration, I’ve previously written about how Android phones won’t necessarily give you as much freedom as you desire if you buy on the basis of price and features . But even the least free Android options are way better than the iOS (iPhone and iPad) environment. This isn’t necessarily a big deal for my friend, like most of the population he usually just wants things to work – being able to hack them isn’t such an issue. However unlike most of the population he does make a reasonable portion of his income from software development and it could be that he will have a contract for developing an app on a mobile device – in which case the freedom to tinker on Android will help him. He could use an iPhone for his personal use and develop on an Android platform for his clients, but generally it’s more efficient if your personal use of technology is similar to that of your clients. The Nexus devices are very good for liberty and they also have nice hardware at a low price, I’ve just got a Nexus 4 for my wife and it’s very nice.
The next issue is that of hardware standards, I’ve previously written about the potential for developing a standard form factor for Android phones  although this doesn’t seem likely to be implemented in the near future. The wide range of Android hardware means that the range of cases etc on the market is rather small. But the advantage of the wide range is that with an Android phone you can have a device that’s bigger, smaller, cheaper, cuter, or faster than an iPhone. There are Android devices which have a higher resolution, more RAM, more storage (if you include SD storage), or has other benefits over an iPhone. For whatever reasonable range of specs appeal to you you can probably find a device to match. I’ve previously written about the way the ideal size for devices depends on your hand size and your preferred manner of gripping the device , so the lack of size range in Apple devices is not just a limitation on personal choice but also a failure to properly support people with different size hands. Depending on the preferred manner of gripping a phone the iPhone 5 is either too big for an average woman or too small for a tall man.
The Google Play store apparently has more applications than the iPhone/iPad App Market. This difference can be expected to increase now that the Samsung Galaxy S3 is outselling the iPhone 5. Comparing the number of unit sales of the iPhone vs Android phones is no longer interesting, comparing Samsung to Apple is the interesting thing.
Advantages for the iPhone
By all accounts it’s quite an easy process to backup and restore all iPhone settings. You can expect that after losing an iPhone you can just connect the new one to your PC and have it work in exactly the same way after all the data is transferred. Trying to do such things on Android is merely difficult if you have root access to your phone and the source and destination phones are of exactly the same make and model. But if you have different versions of the phone or if you don’t have root access then it may be impossible. I welcome comments from anyone who knows of good solutions to this problem.
The iPhone achieved a reasonable share of the smart-phone market before Android really started going well so there are a lot of people who are used to the iPhone. Simply by being unfamiliar Android will be a more difficult option for people who have used the iPhone – such as my friend. But it is possible to learn other systems. Generally I think that this may be a big issue for people who use Macs for all their other computing. But if the only Apple product you use is an iPhone then switching to Android shouldn’t be a big deal.
One feature of the iPhone that is very important to my friend is the ability to add arbitrary tags in the contacts. In addition to name, address, phone number, etc he wants to add arbitrary notes related to his business. While he could put that sort of thing into the “Notes” field in Android he would rather have several fields with his own names. Android 4.1.x definitely doesn’t have this and I can’t test Android 4.2.x at this time. Is there any way of doing such things on Android?
It seems to me that Android devices are better in every way apart from backup, restore, and general management. If I was about to buy 100 phones then I’d probably consider the iPhone (not necessarily buy but definitely consider). But for a single user I definitely recommend Android devices.
The Android devices which seem good at the moment are the Galaxy S3 (which I’m using now), the Nexus 4 (which is really good apart from being unable to change the battery or add more storage), and the Galaxy Note 2 (which is about the biggest phone available).
One of the things that my friend wants to do is to use a phone instead of a tablet or laptop. I think that the Galaxy Note 2 is the only option for him.