"But what is the logic behind this ?"
The logic is that heavier ships take longer to turn/accelerate. Once they reach max speed, however, they are just as fast as small ships.
"How fast and agile are ships are , are just a question about the Size(mass)/engine ratio."
Right - and different classes ships should have turn/acceleration penalties. The design paradigm will be tweaked a bit - you could make a cruiser turn as fast as a fighter, but the cost of how many turn thrusters you will need will make it not worth your while.
"Basicly i am against this, that Shipclass shouldn't give special advances or disadvances, since DW got a free design system. "
Right, that is why players go with one ship name of whatever class and then just pile on/change the components as they research better construction techs.
This results in complete lack of variety of warship types on player's part - perhaps you only need three: a planetary bombardment vessel, a troop transport and the most powerful warship you can design, of whatever maximum size you can. Perhaps a carrier if you are so inclined.
Meanwhile the silly AI is stuck using the Legends legacy of designing silly escorts and frigates by the droves, resulting in your uber warship curb stomping everything the AI throws at you.
To go with your "XXI Century modern navy" example - the US Navy does not have one class of warship. It has anti-sub, AEGIS anti-air, escorts, frigates, spec ops ships, missile boats, patrol boats, torpedo boats, destroyers (all rounders), cruisers...
I am leaving the DW "free design" idea - it is a good one. I AM making ship classes rigid, with size min-max limitations per class, and to unlock a bigger class a new tech research is needed, and bigger ships DO have a turn/acceleration penalty/disadvantage. The big ships advantage is big though (ahhhh, pun) - they can mount many more components/weapons on them.
Late tech thrust/engines will have so much thrust/power that they WILL be able to turn/accelerate a capital ship as fast as a fighter, taking turn/accelerate penalties away - resulting in what we have now in DW, one class warship for the player with no need for variety and different roles... and no need for thinking... and ESPECIALLY no need for tactics.
< Message edited by Timotheus -- 12/19/2013 7:45:13 AM >