I can't see nothing wrong. Maybe, just maybe, your knees are too far forward but it's probably just your anthropometry. I don't have a backside view so I can't see if your knees are shoved out, but they seem to be holding in place either way.
First set is 270, then 2 sets of 260 from a prev workout: (not a great view of the first set, 2nd set is better and 3rd set is a side view.
http://www.youtube.com/watch?v=_d4_b5-Cysc
BW is almost 160. I'm noticing sometimes I will have a really tough 4th rep, but then the 5th one will be easy. I feel like if I lean forward a bit, then it's easier, or I get a good bounce out of the bottom, is this common? If you look at the 4th rep of the 1st set, I have a sticking point that I had to grind through, but then the 5th rep went up easy. It doesn't make sense to me. And what parts of my technique do I still need to work on?
I can't see nothing wrong. Maybe, just maybe, your knees are too far forward but it's probably just your anthropometry. I don't have a backside view so I can't see if your knees are shoved out, but they seem to be holding in place either way.
Watch the depth of your 4th rep vs your 5th. You are going too deep on some reps, and it's killing your ability to bounce out of the hole. You got it right on the 5th rep, which is why it was easier. Also, work on driving hips up, and keeping your shoulders even with your hips, so you get rid of that bit of good morning you're doing when coming back up.
When you say I need to drive hips up, does that mean I'm not using my hips enough, or are they going back or something? Am I leg pressing? I feel it a lot in my hamstrings standing up, but the last few workouts my quads have almost been cramping up after my 3rd set (The 3rd sets have been really tough, but I don't know if that's normal). When I'm coming out of the whole, hip drive is one of the main things I'm focusing on, so if I'm still struggling to do it properly, what are some cues to make it better?
Your hips are going up and back. This is because you are focusing on driving your hips, and in doing so are failing to maintain your back angle. You've got it (hip drive) right, but you need to fix the little error that is introduced when you focus on it too much. This is a good problem to have - all you have to do is keep your chest up and your shoulders even with your hips out of the hole.