RE: Begintermediate on an X-186 Formula (2002 Vintage)
I'm not a team member either, but I do have an '02 X-186, a '91 Equipe XR, and an '01 Start. My weight is 80kg. My most exciting rides so far were on the X-186 with a 5.0 sail and with the 40 cm fin from the Start.
My advice is give the X-186 several whirls before you decide. The X-186 is not the right board for a beginner. You, as someone who could get an Equipe to plane, are a long ways from a beginner, even if your skills are rusty now. You may love the way the X-186 pops up on a plane. A DRAM X-186 weighs just under 22 lbs. It will plane sooner than any other of the other wide boards mentioned in this discussion. The X-186 is 100 cm wide, like a 2001 Start, and only about 4 inches shorter than a 2001 Start. The X-186 is tippier than the Start because of its lighter weight (but planes alot sooner).
I agree with James that Yes, re-learning your skills would be faster on a Start or Rio or GO. But I think you can re-learn your skills on an X-186. I am guessing based on your past skills that your weight is low enough the X-186 won't be too tippy for you. If your weight was 100kg I would guess it would be too tippy to use as your board for re-learning.
After your skills return you will want larger sails for winds under 15 knots. Based on my weight I think your planing threshhold with a 10.0 sail on the X-186 will be more than 10 knots. I'm not a footstrap sailor either.
Welcome back to windsurfing and especially to the planing joys of wideboard windsurfing.