My response is the same as SAKE.
I used to be even more fanatical about windsurfing. About 12 years ago I moved to the Chicago area and the windsurfing conditions here are terrible most of the time. I then had to travel to the Gorge, San Francisco, Hawaii, etc. to get my ya-yas out. I ended up taking up big boat racing for the last 10 years since I couldnt travel all the time
This is my second sumer of kitesurfing and I LOVE IT. My windsurifng gear is in the attic collecting dust.
I had this conversation with a friend just yesterday. He asked me the same question: I told him if it was perfect 4.5 conditions and perfect waves and I had a choice I might go windsurfing. Otherwise the kite is so much easier to transport, set up, ride -and have fun- in 10-35 kts, breakdown, packup and go home with an awesome buzz.
I've had some unforgettable days windsurfing over the past 20 years, but the kite has opened up a whole new world for me. And I don't have unlimited time (or money) to enjoy both, so for me I am afraid that "windsurfing has been cancelled" for the most part.
If you can keep enjoying both though. Being on the water and using the wind is the most important thing.