How player experience is repersented in FM10

Lets say I have two players with identical stats

One is 19 and the other 30

Apart from the obvious answer of future stat degeneration, what tells me that playing the 30 year old or playing the 19 year old would benefit my team better?

Would the answer lie in the hidden stats?

I'm basically asking, how important really is player experience in FM10?

I remember playing a certain EA game a few years back (10 in fact) and seeing bars representing the players experience in their Domestic league and in European competition.

How does FM replicate this, or does it?

From my experience it is shown in the overall shape of his mental stats of the player. But if i remember correctly hidden stats like match importance and consistancy tend to increase as players gain experiance which would therefore translate into the older players being more consistant

It would literally all boil down to hidden stats, which you can kind of tell who has better, within the coach reports.

If all the stats (including the hidden stats) are identical, then the 19 year old will be identical to the 30 year old and there is no reason to play one over the other.

The way that player experience is represented in FM is that the typical 19-year-old and 30-year-old will NOT have identical stats. What happens is that it is quite easy to increase the physical/technical attributes of a young player, but much harder to increase their mental attributes - that takes time. So as that 19-year-old gets older and plays lots of games that experience causes his mental stats to increase - but his physical/technical stats won't increase nearly as much when he is older.