I have a Cocytus SR4 on my Warlock with Firefly and Triple Tap. It hits like a truck and so I've never had the urge to buy Hung Jury. The stability though lower than Hung Jury has never been a problem for me in PVE. I couldn't handle the recoil in PVP, though that could just be because I'm terrible at that portion of the game. Apart from all that, I love Omolon's sights/scopes.
The only problem with the rolls on your Cocytus seems to be Exhumed, which I think is a terrible perk. Grenadier is alright but I'm not a big fan of Life Support either. The choice to upgrade it or not essentially boils down to whether or not you choose your guns based on perks.
Stats wise, I can vouch for Cocytus as it's the only primary I have at 300 plus.
*snip*.