Sony Ericsson Xperia Play 4G (AT&T)

Pros: Good, full-featured controller
Flash support.

Cons: Ugly, bulky and cheap-feeling.
Dim screen.
No HDMI out.
Small internal storage 3/4 filled with non-removable bloatware.
Low RAM - only 512 Mb.
Poor main camera. Front camera is a joke.

Summary: First, the good - the reason most people will get the Xperia Play is the honest-to-goodness controller. At least here it doesn't disappoint - the D-pad and the face buttons feel good. The shoulder buttons are a bit wobbly, but worked well enough. The analogue "pads" were nonsense unfortunately, using them wasn't much more precise than touch-controls, but with one definite benefit of not actually having your fingers obscuring the screen.
The device can run flash quite well - many of the games will be instantly compatible with the controller. Unfortunately - most Android flash players out there don't support the key mapping for more than one action button, so if your flash game of choice uses more than one button - you will still have to use touch-controls.
And this is where the good ends.
Xperia is not a slick device. It's ugly and bulky, and kind of cheap-feeling. The slide hinge feels wobbly, and the rounded, soapbox shape and faded blue plastic put it more in a cheap-toy territory than an cool electronic device. In a surprise move, the device only has 400 Mb of internal storage are ROM - tiny compared to 16 Gb of Galaxy S2, but what's even more baffling and possibly infuriating is that the ROM is out of the box 3/4 filled with non-removable bloatware. After installing less than a dozen apps you will have to start to actively manage your storage. This problem will haunt you constantly, and apps lacking the "Move to SD" quickly become your worst enemies. What makes this carrier oversight even more aggravating, is that Xperia has a hardcore-protected bootloader. It is currently impervious to all existing rooting procedures, so even removing the bloatware by voiding your warranty isn't an option.
The battery life is pretty bad. Even with most features turned off, your phone will barely last the day without being charged. Moreover, it takes surprisingly long to recharge - up to 6 hours!

Cool controller aside, Xperia Play is Android at its worst. It performs like a low-end android device, and has surprising limitations, glaring flaws, and boneheaded carrier software package. If you are going to Xperia after an iPhone - you will really miss the speed and stability of iOS. In my case - I went back to iPhone 4 and was much happier for it, even if having real buttons and not having to deal with iTunes was very cool. I will keep the Xperia around until they find a way to hack the bootloader - and then it will probably become a much better device. Until then, keep hoping for a classy controller attachment for an iPhone: )