Always Slender - I have been using this brand since I was a young teen. The size of the pad is definitely better than most "regular sized" pads. The length and width are pretty good considering that regular sized pads are often too wide to fit on an XS panty. The wings are a bit big though. Absorbency is fine; I have light flow so maximum absorbency is not necessary for me. It is less comfortable than two of the other brands though.
Kotex Tween - Marketed towards young girls aged 10-12, this is a pretty good buy for adult women with petite frames. The size of this pad is probably the best of the bunch. The width is small enough to fit on an XS panty (all four of the pad brands in this review met this criterion) and the short length is the best of the bunch. The wings are the smallest and thus the best. It is very absorbent; probably the (very close) second most absorbent pad of the bunch. Comfort-wise, it is also comes in at a very close second.
Always Teen - Marketed towards girls and young women 13-19. The size of this pad is the worst of the bunch. Even though all four brands have the correct width to fit on my tiny sized undies, this brand is the longest and has the largest wings. However, Always Teen pads make up for their atrocious size by being the most absorbent and comfortable of the bunch. I say dry all day, and zero leakage. Even if you have heavy flow this pad can probably take it.
CVS Petites - The only brand of the four that is marketed entirely towards petite adult women rather than young girls, these pads look and feel similar to Always Slender. Length is alright, width is good, wings are a bit big. Absorbency is fine for me; if you have medium to heavy flow go with Kotex Tween. If you have really heavy flow go with Always Teen. Comfort is similar to Always Slender.
Here is a handy chart of the above information in condensed form:
Verdict: Always Slender and CVS Petites each get ratings of 52% from me. Kotex Tween and Always Teen blow the competition out of the water with 90% and 83% ratings respectively. If you're looking for comfort and absorbency, go with Always Teen. If you're looking for the most physically petite pad (small width, small length, AND small wings), go with Kotex Tween.