Yeah and look ta this one :
XNA racing

And XNA lot lot easy than DirectX , it's simple C# and simple functions to call.
Sometimes some guys instead of waiting engine features could jump on XNA and writes their own needs.

For a racing game , lot of things are not needed and another ones yes.
And you can see , it's incredibly fast , smooth like AAA games on 360
XNA allow direct access to DX with lot of ease.

A last one :
The original shoot on Torque game builder is not really fast , ported to
Torque XNA(combined with gamebuilder for it) , we can see the game running lot more faster.
Yeah XNA Managed code rules.
shoot comparison

Conitec should also follow XNA 2D way i think !

or simply make a XNA solution that would use WED (shader tools ?,
realtime editor ? ) for world nad terrain editing and some other stuff.
But not the scenario users will code missing parts i hate hearing that

Well begin some space ship now , even if it looks really awfull , i'll name my game the Horror 3D space ships