User blog comment:Thailog/Ep. 206 "Bloodlines" discussion/@comment-1268240-20120602184428/@comment-68.36.28.239-20120603005045

Technically speaking, Wally should be faster. A controlled experiment statistically does better, not to mention a) his "undeveloped" pre pubescent body (since it was in his early teens) would be more suspectable to change and b) his smaller body would contain less mass, so the chemicals would be less dissolved.