[Lashcat]

I vote exhaust. That is what I did and I have noe even had a chance to ride it since i bought it two weeks ago. I have to wait for the snow to melt.

[The CyberPoet]

The first mod I ordered for both of my Kats was the Corbin. I don't regret it at all, and it's normally the first thing I order with any bike I acquire aside from safety upgrades and needed maintenance.

The exhaust will make the bike louder. That's it. No performance increase on the 98+ Kats.

The seat will make the Kat more maneuverable (because you sit slightly lower, closer to the center of gravity, and because it's easier to move your body), slightly faster (because you sitting lower reduces your personal air drag) and much more comfortable (because your weight spreads out over your whole butt & upper-thighs -- which means easily riding further & more often).

Cheers,
=-= The CyberPoet