Since a few weeks i use an Apple MacBook Air 11,6" 2,2 GHz Intel Core i7 8GB together with the Apple Thunderbold/Firewire Adapter and a Pacarana.
Honestly i feel that for Kyma it is no so much difference speedwise to the much more powerfull MacPro 12Core i used before i bought the dedicated MacBook Air for my Kyma Setup.
Kyma works and performs great on the Macbook Air and is absolute fast enought even with large Timelines or Multigrids.