I judge people by 3 things. Gear, grimoire and playstyle/know how. Gear and grimoire can give you a very rough estimate of how a player will be. If they have over 2500 grimoire and full raid gear for either raid, I can assume they'll be competent. If they have more than one chase gear, say, FB, a high impact sniper and gjally, I can assume they've grinded their fair share of Destiny. And then there's playstyle and know how. I mostly base this on how heavy or light the load is for me in killing enemies. If they head towards where the enemies are going to spawn and aim, I know they are knowledgeable enough to handle their own. If we get to a certain section of the game and ask "So how do you guys wanna do this part?", that's even better. This suggests they've done this particular section different ways which makes them more versitile. Overall, "know how" is the most important thing I look for, if that wasn't already obvious. When a player looks lost or needs to be told what to do, that's a flag that needs to be addressed. I then step up and tell them what to do. If they can listen and learn, then I don't mind, but if they can't manage to do simple tasks, there's nothing I can do for them and I usually leave. If I have nothing better to do, I don't mind sticking around, but if I want a quick run, I don't see myself working on something for hours when I know it can be done in minutes with the right team. There's always the exception though. If I'm playing with people who are fun to work with and they need help and have underwhelming weapons, I might just stick around and have fun with them. Being the guy that is the only one left at a low life Templar when everyone dies and picking up the relic and one manning the last few shots, or getting constant double revives during the nightfall and feeling like a bad ass can be fun WITH THE RIGHT PEOPLE. With the wrong people, it can be quite the opposite.