My legs have always been a weak point for me, they just never seemed to grow. My training was similar to what you are doing now. A few months ago, I completely overhauled my mindset when it came to training legs.
I split into two days, Tuesday and Friday.
Tues
15 min warmup at walking pace incline treadmill
Squats. Ass to the grass with a pause at the bottom. I stopped going heavy, I was getting strong(385x2 @ 166lbs, 5'5") but not much growth.
3 sets @ 135lbs, 15 reps. 3 sets @ 185lbs, 12 reps, 2 sets @ 225lbs 8 reps, 1 set @ 135lbs to failure(if I have a spotter available)
Leg Press/Calve raise super set
3 sets, 30reps/25reps/20reps of each. no rest
Leg extensions
3 sets of 40 reps
Seated calve raises
3 sets of 30 reps
Finish with 20 min on stairmaster
Friday
Treadmill Warm up
Squats, Again. Same as above
Stiff legged DL's
4 sets of 12, pausing at bottom for a good stretch
Single Leg Hamstring Curls
4 sets of 20 reps
Lying Hamstring Curls
4 sets of 15 reps
Standing Calve Raise/Glute Kickback Super Set
4 Sets of 20 reps
20 Minutes on Stairmaster
Since going to a higher rep program, m legs have really started to respond. I swear they've grown more in the past few months than the last 5 years of training. Granted, I'm not as developed as a lot of the guys on here, but this seems to work well for me. Genetics suck, lol