Yeah I've worked on maxing out my crit dmg as much as I can so I could use the Inna's belt. Now very few witching hours can be upgrades for me.
WH vs Innas belt for Calamity users depends upon other gear (as u wrote in another post). If you are able to maximize CD and Avereage Damage on both rings, you will probably be better with Innas.
However, for SoJ users, WH usually brings better results. For me (I use SoJ's), WH which is equipped at my DH (EU profile) has 5k DPS more then my ex Innas (which had ~170-180 dex).
@Offtopic, I saw couple of SoJ related posts above - same as above, is it good for you or not depends about your dps, other gear and if you care for paper dps or real damage :)
For me, cold strafe SoJ (+CtW) speeds 0-2 farming, cold HA SoJ (+CtW) speeds 3-7 farming, and Bola SoJ speeds mp8-10, compared to my ex quadriflecta ring which I sold for over 300M, and it wasnt so bad. However, with truly godly ring situation could be different, but I am unable to test it, dont have 4b+ :)