For what it is worth...
I'm pretty tall (well over 6 foot) and have chicken legs naturally.
I habge tried numerous approaches to quad training over many years and granted, probably didn't stay with the different routines long enough to really properly test them out. However what I did find out was the following:
based entirely on my own experience - my max has always been around 300 pounds deep squats for reps (when training naturally which has been 90% of my training years which is since 1989 so a good deal of years).
The best way to grow my quads (bar juice which by the way was incredible) was to take my max, which like I say is usually 300 pounds and focus just entirely on that. Do whatever pyramiding up to it - usually 135 x 20, 225 x 20, 265 x 15 then the meat and potatoes sets. Always do 10 plus sets including the lead up sets (10 min and then whatever I can make happen on the given day).
So - I know that even on a bad day I can do 8 reps of 300. I also know that I can then do a further 6 sets of 6-8 (I could be struggling but so what).
What I try and do is go for broke and knock out just as many reps on the 1st and 2nd sets of 300 as possible. There was a time when I got the reps up to 20-25 and then over the last 3-4 sets would be getting about 12 reps a set. Didn't go heavier as the work load was so intense that if I had i would start to use too mcuh back and hams etc.
But what i found was that by gradually pushing for those extra reps but staying at my chosen maximum weight I gained more quad size than at any other time barring taking gear.
As it happens I'm off to train my matchsticks tonight. Hopefully it'll go to plan tonight.
Oh - and by the way - when I tried doing much higher reps on lighter weights I found that my legs didn't grow but definately got alot harder and seperated - but not bigger.
