The info given so far reinforces some of my thinking. Plus the different boats, where they are sailed and how much gives some ideas of what's working for others. Some surprises too.

I'm replacing a 150% with a smaller 135%. My only reservation is, should I go a little smaller? On my last boat with hank on sails, I did most of my sailing with a 120% only hanking on a 150% in extremely light air, and then only if I had to go to windward. Off the wind, the big sails area was useless. Not only was the 120% usually the faster sail all around, it was much handier. Our current boat has a much higher SA/D and is a better all around sailer.

And handy is one reason I'm going to a smaller sail on the furler. We like to sail in and out of anchorages and harbors. Often the little added speed of our big genoa in tight sailing is lost in our tacks. By the time I get the big sail on the next tack and drawing, I've lost a good deal of way. I have self tailers but even working fast (myself), short tacking in light air is a clumsy operation with so much cloth to move. I don't want to knock myself out either.

For this reason, I'll sometimes roll up the 150% to a more manageable size, but you know what happens then. In the end, for me, this results in doing less of the type of sailing I enjoy. I want to make my sailing easier so I can do more of it.

And then I find the 150% off the wind with my boat, it's too much cloth to get a good shape.

My local sailmaker is confident with a well designed foam luff, the 135% rolled to 120% will still have an effective shape. 100%, not so much to windward but a very "handy" size for short tacking if the winds allow.

I know my boats sailing abilities well enough to know the 135% will increase my overall speed. Just off the wind, it will be more efficient than a 150%. And while dropping down to a 120% is tempting, especially for the ease mentioned above, we sail in quite a bit of light air here in Penobscot Bay and the boat is up to that. I'm afraid I'd lose just enough of that ability with the 120% that I'll not likely go that far.

And for the coastal sailing we do, we're not likely to change the headsail so it needs to be the best compromise. There's very little furling ability to work with in reality. I'm asking a lot from one sail.