I want to start tracking hours at my current employer for Android and iOS dev since they are for the same apps. Anecdotally what I've seen is that iOS finishes faster, with way less hiccups and compromises.
I wouldn't say it is a huge factor. The biggest by far is that each manufacturer/carrier has a slightly different implementation of Android to the next. I have seen small Android projects that have hundreds of defects despite the factor being implemented exactly right.
