Default [Q] Improvements by "updating" bootloader with stock 4.4

Hey guys,

I unlocked my bootloader some months ago (my Z1 came with stock 4.3) and use SlimKat (weekly ATM) since then.

Now that the official 4.4 update is released, I wonder if there are any advantages (like better cam, wifi, newer modem) from locking the BL, installing stock 4.4 and unlocking BL again, to go back to a custom ROM.

I come from a Samsung device where you could update e.g. the modem/baseband seperately and I understand that in Sony devices all these things are fix in bootloader.

Thanks for your help!