RE: Flare or Kombat '06?
1) Early planning
Flare, but with some technique the difference is minimal.
2) Popping (flatwater)
Flare, no doubt.
3) Jumping of a ramp
No big difference. Different feel, but hard to say either is better than the other.
4) Response in footsteering, gybing, carving, backside waveriding
Kombat. The Flares jibes great, but preferably with a super comited style and even then quite drawn out, alsmost race jibe style.
Flare. Kombat is good too, but the Flare just glides better and accelerates faster.
6) Upwind with a 23-25cm fin
I would say Flare, but in 4-strap modem the Kombats will in practice work better because you can get a more effective stance.
7) Top speed
Same as 6. Flare has a faster bottom, but when you're really powered up I think you can go faster with the K with the right trim.
8) Non-planning freestyle
I would say the Flare again.
The thing the Kombats do MUCH better is anything that has to do with wave riding and I would also say most people will find the Kombats nicer overall for "general sailing".