Having gone to all the trouble of widening my Stealth from the original R to the new F16 width, I would quite catergorically say don't bother. For all the time I spent changing everything on the boat to accomadate the extra width such as tramps, rudder connections, etc I would have been far better off spending time on the water where I would have got more gain than the 1 - 2% predicted and saved quite a lot of money.

Equally the boat behaves quite differntly with the wider beams, I personally think over all the wind strengths below fully trapped out, the boat is actually faster upwind in its narrower guise, other Stealth owners have commented the same, but at higher wind strengths the boat is much easier to handle, certainly out on the trapeze it feel much less flighty and "chilled out", its surprising how those extra few centimetres slow the heeling speed down.

So if you have one of the older style narrower boats, don't bother, just save your pennies and enjoy your sailing, it makes very little difference.