Hi guys,
thanks for the beta-testing!
I'm the developer of the PowerAMP.
The version you tried is pretty early beta version, released only to one of the internal russian sites for some early limited core functionality testing . The next beta will include all the bells and whistles you mentioned here (like various sortings, better headsets support etc).
Early beta is important for devs as it shows how the app will work in general in so fragmented Android population.
The gapless playing and other audio processing related features are planned for 2.0 version, but not for the first release. Though, delay between the tracks introduced by player itself is minimal (esp. compared to other players).