I just mix my tracks and play them from any available device on the gig. Used to be a(and sometimes still is) an iP{ad Pro, so I can also include my GigTracks scores and iRealPro tracks for requests i know but haven't sequenced. Now I can use my iPhone or any of the iDevices I have for backup. PLUS I get to edit out the inadvertent clashes in the guitar or bass channels. Fast edit, everything's 1 or 2 bars.
Then really any WAV or MP3 player will do. Works great for me, although I would love to be able to hit F4 on that third blues of the set...
It's all about the music.
(I keep telling myself that...)