I can't see much worth commenting on in the video, so I wont. Someone else with a far better eye for this sort of thing than I have may come along and tell you to read the video stickies. They will probably use the word "cleverly". Fair warning.
However, it seems likely to me that you may be using your adductors more with your current form than you were with your previous squat form. That tends to make things sore.