Thri-Kreen can be pretty ridiculously overpowered if you know what you're doing with them.

Thri-Kreen Warblade (or Swordsage). Max Concentration and Jump. Fight with four kukris, MWF, the Blood in the Water Stance, and whenever you can't use a full attack, use a Nightmare Blade or a Jump-based Strike. Yikes. This general build is a great melee combatant even with a normal race (like Human), using two kukris; adding two more kukris and a +30 bonus to Jump checks just gets crazy, even with the RHD and LA that slow you down.