I'm using this bag to keep a small Rock Band 3 25-key keytar controller (which I use as a MIDI controller).
Not only it fits perfectly (a very common issue with keytars is that they tend not to fit common keyboard bags), the MIDI-USB cable fits as well without any extra pockets.
The only downside I can think of is that the zippers sometimes get jammed due to the materials not being the best, but really, for the price it's a great keyboard bag.