If you want to stay on 15.0.3 you might want to consider applying patch ESD #4.4 instead of ESD #1
15.0.3 ESD #4.4 is the latest ESD on 15.0.3
It would require the same amount of testing as upgrading to 15.0.3 ESD #1, and saves you the trouble of another patch install later on.
depending on your installation, you might have to run other install scripts.
e.g. when you have dbccdb installed for checkstorage, you should also run installdbccdb
use procedure sp_version to check what you have currently installed, and apply all required scripts from the new patch level