Jerry Montgomery, the designer of the Sage 17 & Sage 15 and a guy of strong opinions, wanted to add this to the discussion –

The [Sage 15 and Sage 17] sails way better with a small jib and a reefed main. All boats of this type should have a storm jib – if the winds looks like it’s going to come up to 25 or so, put up the storm jib; you’ll be amazed at how little it slows the boat down to even in a 15 knot wind (unless you’re in a race!). You will seldom use [a storm jib], but it’s invaluable when you need it, and you’ll save a lot of wear and tear on the other sails. Storm jibs don’t cost much.
Once in Mexico I [Jerry] used the storm jib every and all day and had no trouble keeping up with the other boats. It was blowing 25 and 30 every day
NOTE: I originally posted this January 2018 on Sage Marine’s BLOG. In a short time the BLOG will be closed – stupidly. I am reposting this information so it is not lost.