Once you learn the particular phone, it's amazing how fast you can open an app, change something, get some information and close the app. I've seen people do it on an iPhone as quickly as I can do it with an Android widget. (Then again, my daughter texts at about 60wpm. I'm lucky if I can hunt and peck on a phone, but I can type faster than she can on a real keyboard.) What you're good at you're efficient at. It's more the level of experience than the phone.
As for security, if it's connected to the internet, it's not. A phone, a desktop, a washing machine. They haven't found a way to send a virus down a powerline (yet, as far as I know), but they used to say that Linux was secure - until someone almost brought the entire internet down. If you want security, write it on paper and burn before reading. Then mix the ashes with water and stir.
If a good Windows phone had come out before Android, I'd probably be on a Windows phone (I can write Windows apps, I can't write Android apps yet), but everything I do when I'm not at my desk is Android, so I'm kind of committed to it - and I can find an app for just about anything I want to do.