I have always sorted my playlists by Artist/Album/Track Number. It makes it easier for me to navigate my music collection, queue up tracks in a certain order, and more easily manage my entire library. With Poweramp, I've noticed when I sort by Artist/Album, the track number is not taken into consideration; which makes navigating my playlists more time consuming and difficult to manage.
When shuffling tracks in a playlist, I prefer to keep the playlist in the correct order and have the playback queue reflect the current "shuffled" state. This way I can utilize the queue to alter the playback order or add/remove tracks, rather than altering the playlists.