Hi guys, pure-gunner here.
Here's my story. I was originally going to go with a full Justifier armour set, thinking "damn those wolvers, out of all these gunslinger alchemy-paths i'd like piercing resist most". Then when I got a gunslinger sash, I was underwhelmed with the speed improvement (I was going with a cryo alchemer and a shadow alchemer at the time, so bear with me). I decided it surely can't be that good, so I thought I'd get a mercurial set because movement speed would surely be a universal thing, so if I pulled out some bombs or something, I wouldn't be any worse-off (pardon that ignorance :p).
Anyway, now I have a charged quicksilver armour and helmet and I'm worried it won't be worth upgrading them to mercurial because of the underwhelming boost to movement speed... and now I'm thinking maybe I need to go back to the gunslinger stuff, only not on the justifier line... I'm just really concerned, like there's no really great armour for a pure-gunner like myself. Oh and as for the whole alchemer thing, I'm now running a Virulent Catalyzer and Firo Driver, and I'm relatively pleased, but working on getting a magnus as a third gun...
So I'm just looking for some advice. Clearly selling my armour off would cost more than it's worth, but I may just keep them for costumes anyway... but I have no idea what armour to change to if I do decide to give up on a mercurial set.
Keep in mind I am a paying player, so starting from scratch isn't too much trouble for me, as I'm happy to throw another $20 at OOO to continue to pay.
Mercurial is really only good as a costume, because it's really really cool looking. If they increased the move speed to medium/medium it might be worth the lackluster piercing resist but you're best off using either a nameless set for the barely noticeable attack speed increase or a more defensively attractive weapon neutral set like grey feather. You'll do more for your damage output with 2 elite trueshot modules than any bonuses from gunner specific armor anyway, so grab those and then dabble around with different 4 star sets to see what you want to sink the 800 energy upgrades into.