I have a TAK in D2 great knife, but yes the sheath does suck. I made a new one out of Kydex and was really happy with it. May have to redo my belt loop on it, but I just might get a Tek-Lok for it instead.
Anyhow I would love to jump on some new Rat designs, kind of holding out for the Izula (sp). I'll have to see what it costs but the knife looks great.