So I get what you are saying when it comes to those Differences, but for the most part IMHO they are quit small and don't make the two heads VERY different. However, that is subjective. As for the PF being accepted as the better version, I haven't seen any real evidence of that. In fact if I looked back I bet a lot of people would argue the opposite to this.
I'll agree with you, they aren't "huge" differences but the slight changes make them look very different.. Let's take an anatomical look.
We'll go top to bottom.
The Eyebrows, obviously as everyone has pointed out, The PF has more realistic eyebrows while the LSF has a more comicbook styled brow.
The Eyes are diifferent shapes. The PF has a more rounded eye and LSB has thinner eyes, and they seem a bit longer.
The Bridge of the nose. The PF's thins as it reaches the brow, LSB's remains square.
The Cheekbones. The PF's are thinner and protrude less. The LSB's are rounder and more noticeable.
The Nostrals. The PF's nostrils thin as the go back, the LSB's remain rounded.
Mouth, almost no difference except for the PF's mild frown, were the LSB's isn't.
Jawline, very small, the PF's is slightly sharper where the LSB's is slightly more rounded.
Chin, obviously the LSB's is more pronounced.
Did I miss anything?
Okay now let the argument continue.