Without loop, transposition and tempo adjustment features in any built in player, doing song learning on the keyboard's player is an exercise in futility.

What I don't understand is why everybody that has a decent arranger doesn't have a computer standing right in front of it at home... Firstly, just as a simple backup solution, and access to transfer web-found styles and songs (or MP3's ) directly into it. Then, of course, there are all the other benefits like access to audio manipulation programs (Amazing Slow-downer, etc.) that make learning songs a snap, use as a VSTi host for adding high quality sounds to your rig, use of DAW programs, to make producing your music from start to finish easier, use of loop production tools, to make producing more contemporary music a snap... The list goes on and on

A computer desk that the arranger sits on, monitor front and center, a pair of decent nearfields to either side, and a drawer underneath with the mouse and computer keyboard on is music making heaven! Something with this kind of form factor: http://www.officedepot.com/a/products/620495/Office-Depot-Brand-Computer-Cart-With/ makes for a pretty efficient workstation (mine is a different brand, and is modified to get the nearfields further out and well supported, but the type is the idea).

Now you don't NEED badly thought out arranger audio features!