I made the biketard in size L for my daughter, who is a perfect L in width and halfway to M in height. Since I was using 4 way stretch cotton lycra, I just went ahead and made a size L with no change to length. They are perfect. They fit her exactly, sit on her comfortably and she is particularly pleased with the legs area, which gives her coverage but does not apply excessive pressure (as leotards with elastics do). I intended to use elastic at the neck and arms but then saw the pattern's method of creating a self-fabric binding in lieu of elastic and tried that. The instructions were easy to follow (I looked up a Jalie video explaining the technique, to be sure I'm getting it right) and the result looks very professional.
There is NO elastic involved, only lycra fabric, for the biketard.
I believe the people who complained that the legs are very tight might have tried to sew the front to the back directly and omitted the crotch piece. The crotch (on the biketard, not the leotard) is not just a lining - it is an insert that is stitched to the front and to the back pieces, respectively and increases the pants area leg opening size. Once the crotch piece was in place, the result was a well-fitting bottom section, made extra sturdy by the lining (in effect, giving a double layer between the legs).
I'll definitely be using this pattern for more biketards, and I plan to make the leotard my basic pattern for creating various designs of color blocked leotards for my daughter.