I bought this primarily for keeping some small emergency drum kit in my backpack while gigging and practising and I am now using it for carrying around some more important gear such as a portable phantom power supply and a small preamp.
So yes, the space available is enough for these thing, good protection and easy access to all you have put in there.
The zip closes the bag properly, it looks nice and the overall quality is really good. I think I'll buy another one in the future for the original purpose.