I've owned both for long periods of time, and compared both.
I ended up selling all my Cheetah several years ago for the Sky.
Cheetah is quite good, but if you want the best, you want Sky.
Sky has more low level detail and less distortion. Highs are cleaner and they sound more like "no wire" when compared directly to Cheetah. Cheetah provides most of the sound of Sky, and costs a LOT less. I believe the conductor sizes are slightly different, and the insulated tubes holding the conductors are larger (so less insulation actually touches the silver wire). Flexibility is better with Cheetah.
Hope this helps.
Will
I ended up selling all my Cheetah several years ago for the Sky.
Cheetah is quite good, but if you want the best, you want Sky.
Sky has more low level detail and less distortion. Highs are cleaner and they sound more like "no wire" when compared directly to Cheetah. Cheetah provides most of the sound of Sky, and costs a LOT less. I believe the conductor sizes are slightly different, and the insulated tubes holding the conductors are larger (so less insulation actually touches the silver wire). Flexibility is better with Cheetah.
Hope this helps.
Will