i use the bag mostly for my trumpet and my mutes, to go wuth my bike or by foot, it sits fairly comfortable, but needs bigger sheet pouch. 
in the main part of the bag fit: 
2 trumpets and mouthpieces without danger for damage to the trumpet 
or 
1trumpet and 1 straight mute with cup, practice mute, pencils, oil, cleaning products and mouthpieces without danger for damage to the trumpet 
 
pro's , very useful for a student who has to carry his trumpet everywhere or with the bike. 
con's, i need a bigger pouch for my sheet music because an slightly bigger map than an A4 doesn't fit really well and damages my sheets