Xperia Play here.
The four (including the Xperia Play) Xperia are a triple assault by Sony Ericsson on the Android market. Each has its own distinguish features. The Xperia Arc represents Sony Ericsson new Xperia flagship, an ultra slim smartphone with a large 4.2" screen. Sony Ericsson has also catered for users wishing for a hardware QWERTY keyboard - in this case, the Xperia Pro. Finally the Xperia Neo is a mid-range phone that shares many of the features found on its more expensive sibling, the Arc.
Of the four devices, I spent the most time with the Xperia Play, hence why I thought it deserves its own post. There were only one or two Xperia Pro in the event, so I only got to play with it for a couple of minutes. The slide out QWERTY keyboard feels good and the keys had good travel. I also like that the keys are well spaced. However I can't comment on how well the keys are in real life usage. Hopefully I will be able to acquire a review unit.
Both the Arc and Neo has similar performances. There were slowdowns but the Sony Ericsson rep has told us that this was because the units were running on preproduction firmware. They all run on Sony Ericsson's Timescape UI which works well. The homescreen can be zoomed out, but unlike other Android launchers, you get an overview of all the widgets currently active. Press any of the widget and you will be brought to the correct homescreen tile.
Sony Ericsson has not confirmed pricing for any of the devices. The Xperia Arc, Neo and Play are said to be launching in March 2011, with the Xperia Pro arriving in April.