I'm due a phone upgrade on June 28th, and it cannot come soon enough.
For the last three years, four months and thirteen days, I've been using webOS phones. Starting with the Palm Pre when it came out, I've gone through the Pre2 and now use the Pre3. I love webOS, and nothing else I've used has convinced me that it's anything other than the best-designed and easiest-to-use mobile phone operating system that's out there. Sadly, nobody else seems to have agreed with me (least of all HP, who until three days owned webOS, until they sold it to LG), and since neither Palm nor HP had the money to really push the boat out on proper hardware it's actually pretty easy to see why.
webOS has always been a bit sluggish, its usability hampered by slow responses to user input. Occasionally the phone's multitasking will cause the entire device to freeze for a few seconds, leaving me incapable of even closing the offending app. My phone occasionally won't switch on the mic when I make or answer a phone call, leaving me muted. The browser runs out of memory with more than one card open, which effectively cripples the whole point of a multitasking OS, and will randomly reload an entire page or fail to render more than one screen's height.
I find it really difficult to use anything else, though. The best thing about the Pre series of hardware, which I desperately wish other companies would steal, is the the gesture bar - a touch-sensitive panel that runs off the bottom of the screen. I'm so used to the Pre gestures that I do them automatically on any other phone I pick up.
Come June, I'm probably going to pick up a Windows Phone 8 device1. It's probably the operating system that I've used least of the three big names currently on the market, but I really like that it's trying to distinguish itself from Android and iOS' boring icon grids. I'll probably take a few weeks to stop trying the back gesture, though.
1 What can I say? I'm committed to the underdog.