Android’s greatest strengths are capability and choice. You can pick the form factor you want, for the price you want, and do just about anything on it that you want to do.
The downfall is the manufacturers themselves. Left alone (vanilla Android), the OS is very solid and capable. It runs quickly, and can be easily customized. The problem is that OEMs like Samsung and HTC come in and modify everything to look and feel a certain way. Some of these mods are good, and some of them are very, very bad.
Each mod, whether good or bad, comes with some sort of trade-off. Maybe a Samsung phone changes a setting differently than an LG phone, or maybe a shortcut isn’t where you expect it. Worse, almost every single cosmetic modification out there seems to slow the phone down or drain battery life
So, the biggest problem with Android is the people making the hardware. You can get around this by buying Nexus devices (which I like), or by choosing a manufacturer that only lightly modifies the OS.
You want my advice with Android? Stay away from Samsung, and buy something from a manufacturer that’s doing things right. LG’s recent devices (like the Optimus G and Nexus 4) have better build quality than any Samsung on the market. The Galaxy SIII is really a pretty cool phone, but the plastic feels a little flimsy and it seems to me like they’re cutting corners with build quality. The screens look great, but the software is bloated and man do I hate TouchWiz.
But I digress. The point is, if you want huge battery life, you can buy a Motorola Droid RAZR MAXX (terrible name). You want a giant screen? Grab an HTC DNA or Samsung Galaxy Note II. You want productivity and a physical keyboard? Buy a Motorola Photon Q. If you want cheap, buy a slightly older, but good, model like an HTC One X.
My point is that, with Android, you can buy the device that fits you best. The only downside with that is that there are so many choices that it pays to be informed before you go to the store to buy something.
Oh, and don’t believe the malware scares and all that crap. Yes, there is malware for Android, and yes, there are a lot of different versions of the operating system, but it makes less of a difference than you may think. Don’t like your OS version? Root and install a new one. Don’t want malware? Don’t download illegal apps from 3rd party app stores or from shady websites.