PVP Weapons: What's good? How do I tell a good weapon from a bad one?

So I've been trying to get my hands on some weapons for PVP, and I see a lot of slang thrown around when it comes to "good" PVP perks, and good PVP weapons. But I can't make heads or tails of it, and I can't seem to find any guides that explain it, except ones that say "This weapon is good, this one is bad, etc."

For example, I ran Skolas the other day and got a Y1 Red Death. I upgraded it to a Y2 Red Death in my blueprints, because I read that the gun was good for PVP. But after looking around, I began wondering: do they mean Y1 Red Death, or Y2? How does that even work with PVP? Does it matter? Which one is better?

Also, early on, I got a Hawksaw that I used a lot in PVP, but it wasn't really hitting very hard so I stopped upgrading it and sort of let it gather dust in my vault. But the other night, someone was bragging about a "max stability Hawksaw" they have. Apparently that's good? I checked out my Hawksaw, and it has perks that let me make it max stability and max reload. Is that something I should be using?

Finally, I joined a group for Grasp of Malok farming last night. I really wasn't looking for Grasp, I just needed to farm some engrams. But they talked a lot about Grasp, and wanting a Grasp with certain perks. Why is Grasp considered good?