Comparing players: grey skills vs white skills

[Toxcatl]

that skills are cosmetic ?

You don't know that. Me neither, but I think you're wrong. I seriously need to gather all the facts about it and make a thread with arguments for and against. Just for, you know, settling this in my head.
Ah, I hate being agnostic, though sometimes, like in this case, there is no other choice.

When I'm looking for players on the TM, I often compare players on auction with my own of the same role.
Very often I find that even though the auctioned player has higher quality %, his white skills are more or less at the same level as those of my own player. The difference lies in the grey skills only.

You need to consider other factors that affect training pace: age, stars and, ideally, talent. The last one is a bitch though. Read Nik's guide about FTs to get more info, if you haven't already.