I have an over watch precision with their minus connector. I highly recommend it. I saw a zev trigger fall apart on the range last week, so for me they are out.
What are we using this for? Carry, competition, shits and giggles?
If you really want 3.5lb pull you will be doing more than just a trigger, going to have to change out some springs and maybe a the safety plunger at minimum along with the connector, the trick is finding the combination.
2 triggers I will say stay away from 100% would be they pyramid trigger and zev.
I have an Agency Arms (trigger shoe, OEM polished trigger bar, polished OEM minus connector but that was bent so I need a new one) that I really like.
I have finger fucked an Apex trigger that I helped a buddy put in his G26 (just the trigger show and polished trigger bar, not their full kit) it was also really nice but I think their glock trigger us ugly AF.
I also really have been looking at the Overwatch, I think if those were out when I first started looking for a new trigger I would have went with that over the Agency (I think the agency looks a small bit better aesthetically but that's just my opinion) and I am waiting to order their NP3 coated minus connector for my G19.
If you really want to go down this rabbit hole check out Tactical Toolbox on YouTube, he has the best range of different glock triggers and combinations, his videos are good but a bit self prompting (but he is trying to make money so I'm ok with it)
I have the Apex Action Enhancement kits in both my G17 & G19 and love them. I think they're a HUGE improvement over the factory trigger, but you won't get a 3.5 lb pull from them. My G17 measured out at 4 lbs 7.6 oz.
I tinkered around with a Ghost Edge trigger kit for a while. Connector, trigger spring, firing pin spring, and a reduced power safety plunger spring. Makes for a very light and smooth trigger in the Glock. And it was only around 35 dollars shipped