I did demo after sharpshooter and leveling up a second wasn't bad. I hadn't done any bounties in ages, so plowing through all the Tusk ones got me enough points to max out grenade launcher damage and explosive damage. Demo is a strange bird compared to sharpshooter. Where sharpshooter has a lot of good passives and the spec gun is garbage 90% of the time, demo has fairly crappy passives but the grenade launcher is ridiculously strong, and I don't even have any +20% explosive dmg perks on my armor. I still don't understand the ammo dropping for it though. Sometimes I'll kill a bunch of dudes with grenades and get no ammo, then I'll run into a random and just light him up with my AR and he will drop some without a bit of explosive damage done to him.
Pro-tip: any time you're out of GL ammo between missions/bounties, just fast travel to the WH and swap specs to something else then back to Demo. You'll get a full load (6/2) of ammo and don't have to dick around trying to get more to drop.
So anyone got any recommendations for good talents to look out for (or a guide)? Janx mentioned Clutch, which you can find at the Theater vendor (gloves) right now as well.
But I'm not sure what weapons mods are rare, nor what to look for with armor. Leveling to 30, I mostly ran AR/Rifle.
(I run a tanky but high [enough] dps build for AR/rifle and solo 100% of the time. So YMMV depending on how you like to play. Also, I'm not going to list what each of these perks does, just look them up in the spreadsheet for reference.)
I find Patience to be absolutely required. As long as I stay in cover and don't get flanked by an LMG dude or one of the throwers with their ridiculously OP SMGs I can tank a hell of a lot of damage without needing to constantly drop chems.
Berserk is very strong DPS, but I run AR/rifle so would only get the benefit ~half the time (less in actual practice, at least against challenging content). Since I already have 7B for Patience, and have just over 190k armor before any buffs, I use Unstoppable Force on my chest instead. Plus I'm rarely below max armor thanks to all my healing effects so I wouldn't get a lot of use out of Berserk.
Clutch is good, I use it since switching back to a crit-focused build (which was only really possible once I unlocked the +crit/-hsd scope from control points), but you do need your crit maxed or damn close to it for it to be worthwhile. You also need a high rpm weapon, but I'm ok with only really getting healed by my AR since I don't really worry about healing when at rifle range.
Safeguard is fantastic when combined with other forms of healing, even though it apparently got nerfed to 75%. Mine still says 150%, but people on reddit were saying the nerf happened already(?).
Dialed In was broken OP for a few days, but I think the nerf made it just "OK" now. I only have one mask with it, and haven't bothered testing it yet.
Fill'er Up is really nice if you use stuff like 100 round LMGs and one-shell-at-a-time reloading MMRs like the Model 700. Could combine it with Frenzy on the LMG as well, but the best trick is to carry a double barrel shotgun for sidearm and fire it blindly and reload it to instantly reload both your primary guns. I just use 8% crit on my holster though to get close to the 60% cap.
For weapons, I prefer Ranger on my rifle and Close and Personal (or Strained if you don't mind being hamstrung by its <=5R req) on my AR. One gun should have Protected Reload on it, the other I take what I get since there's more important thing to recalibrate. No idea how to test how much of an effect Overlap has, and frankly I still don't even really know what the hell Weapon Handling in Div 2 does (anyone?)...but maybe it's worth having. For the middle talent, I always prefer Extra ammo, but you can't really be picky there either unless your gun was a godroll to start. First Blood needs a mention because it sounds great but is broken and doesn't actually do anything currently.
Pistol = Liberty exotic. And I carry around a backup sidearm with Transmission on it for when I run into a bounty with some asshole using shock rounds & grenades.
Sadly in order to get all that stuff on my gear how I wanted it, I ended up with 6 pieces from 6 difference brands, and I have to use a ACR-E instead of the CTAR or F2000 or Police M4 that I prefer. No way in hell I'm putting in the time to farm it all up the same way and also have a 1/2/3 or 2/2/2 setup when WT4 is just going to be obsolete soon anyway.