Basically, to quote:
Performance
Performance for TS2009 stitched track is considered superior to all previous track implementations. Actual performance penalties will vary based on the following factors:
* Distance at which the High-detail LODs drop out. Generally this should be extremely close.
* Number of polygons in the lower LODs. Generally this should be very low.
* Number of materials used. Ideally, a single material is used for all meshes, rather than one or more per mesh.
* Length of each mesh (longer is better).
* Efficiency of the "track-lod-tree" container.
* User-customisable detail settings.
* etc.
So there's an awful lot of stuff to get right to get the most out of this method. If you really want a headache read this: http://online.ts2009.com/mediaWiki/index.php5/"track-lod-tree"_container
As I understand it, it's quite expected that the high and low detail meshes will be different lengths, so a well produced new track should not get kinks up close. It's also possible to force the game to use the shorter hi-detail mesh for short sections in the distance to avoid kinking.
What we really need is tutorials/examples...
Paul