I'm developing cross platform apps, so at the moment have an iPhone 5, a HTC 8s and some LG Android phone. I personally have a L920 too.
I've been playing with the iPhone since I got it last week, and to be honest, I'm not impressed.
I had a iPhone 3G when they came out, and at the time nothing touched it, but now it is just a bit dull. Having to come out of an app to change its setting! Buttons so small that i have to prod it 2 or 3 times for it to register! No widgets or live tiles, with only stock ones showing a number above them! I also had wifi just drop out for no reason while streaming(wasn't the router as my 920 was fine).
The only positives are app numbers and battery life. Although that could be because I'm hardly using it.
The one OS that does look interesting to me is Ubuntu, which should be released later this year. It seems to take the best bits of every OS. Might try and get a Galaxy Nexus and install the development version soon.