Nino, from my limited experience with Stern machines, 2 x AC/DC and a Metallica, I would say that the TWD playfield you have there is pretty much the norm.  Both of the AC/DC machines were much the same and then as others have mentioned, after more and more plays, the dimples seem to blend in to each other and are not as pronounced.

I wouldn't move posts just for the sake of it, not worth the risk of damaging the playfield if you don't have to.  I was devastated when I saw what happened with mine.

Stern playfields are what they are.  Be aware of this when you buy a brand new Stern machine, it is nothing new so don't expect anything to change just because you bought a new machine.  The way I see it you have two options.  Source a 2nd playfield, get it cleared by HRP and swap it over or just accept it for what it is, play the machine, enjoy it and be thankful that there are new machines available to buy and play.  Third option, simply don't buy one.