I would know if the choice of the start level for my user bundle a is important.
in fact, i have few dependant bundles and they start in the correct order even if the have the same start level.
I work now in fuse esb 4.4.1; but before with the 4.2.0, the start level was obligatory.
but i didn"t find this information on th migration guide.
If you didn't introduce some third part dependency bundles which need to be started first, you don't need to setup start level on you bundle.