Keslers, as all new modern, race boards have variable radius where nose takes nice tighter cut and tail of board has much larger radius allowing you come out of turn with good speed.
I have Coiler NSR's 168-183 sizes wich feel very similar to latest Kesslers, i tested few of them in last spring cause guys picked some of them here :)
My small 168 has 12.7m radius on nose and 18meter on tail and it is great toy to keep good speed on local small slopes.
I had my 183 on Oppdal last winter and it was pure pleasure to run slopes downd there with that.
If i want to go high speed, then i pick my 202 Tinkler, there is no speedlimits with that, and it turns when made to turn ;)
And if you want to stay with splitails then you can pick Burner:
http://www.ojankaivajat.org/forum/viewtopic.php?f=34&t=2364
http://www.flegmatic-carving.com http://www.youtube.com/user/FLEGMATICCARVERNSR