Notice most of the currently practicing hydro guys are all saying one of two things.
1) start hydro from seed or clone instead of forcing your plant to adapt from primary soil roots to primary water roots.
Or
2) the plant doesn't look too bad for a young plant to me.
And they are right in both cases for multiple reasons. Most plants have the ability to be grown with primary water roots but you don't want to confuse the plant by making it change over in the middle. And right now your looking at your plants side by side saying damn my soul plants look greener healthier and more vigorous but your not seeing the true root zone difference. In hydro during this initial "rooting" phase in its life cycle your forcing your hydro plant to do 3 times the root work of your soil plants so they do tend to look less verdant at this stage don't sweat that. Once she dangels her toes in the solution and gets well established she will make up the difference and then some on the early soil head start.