Konas is an utility mod known well in the CrystalPvP and anarchy community for its low price and great CrystalAura. Other good combat modules are Aura, AutoTrap and Surround. The client is mainly developed by Darki.
As said before, Konas has some great combat modules, including Aura, CrystalAura, Surround and AutoTrap.
Konas also has a rather wide variety of great movement modules like Strafe and ReverseStep/Step. They usually work flawlessly, but no client is perfect.
Konas' visuals are great. They include great ViewModel, Nametags, ESP and Chams. This, however, is another client with no SuperheroFX. Reality is often disappointing.
Other miscellaneous modules in Konas also work great, like PacketMine or Offhand. They work well and never disappoint you.
The client costs 15$ with rather regular discounts. This is great value for what youre getting, considering the CA is flat-out amazing against other clients. Support with this client works well, you dont need to wait too long for an answer.
Conclusion: Amazing client for its price. Only con I can think of could be the complexity of configuring some modules for beginners. Now that it comes with a version chooser, its definitely worth 15$.