When I bought my Peterson 43 (used) it had a full complement of sails including both a light and heavy blooper, double head rig, blast reacher, tallboy staysail, on and on. It was the last boat that I have owned that on which many of the specialty sails worked to increase boat speed when used in the right conditions and at the right angles. I attibute that to the nature of the rig for that boat--high aspect main, masthead, very big fore triangle that was the rule for the early successfull bigger boats under the IOR. As advantages of fractional rigs, larger mains, smaller jibs move up the fleet from the small boats the bloopers on larger boats disappeared as they did not work. Under, ORR, IMS and IRC they are prohibitted.
I used the heavy blooper a lot on long races and the staysails both genoa and tallboy a lot. If I still had the 43 and was racing PHRF which permits the blooper I would still use it (but not on a 1 mile windward leward race).
Unlike many I never considered the early to mid era IOR machine's unstable down wind just more difficult drive well. No question current boats have more stability and are much faster in every way. My Sydney 38 rates PHRF 27 while the Peterson rated PHRF 60 or 57. But we had really great racing--I have a small picture on my wall of a local race in Chicago that has all of the boats in IOR section 1 racing that day (olympic course -- not yet endless W-Ls) with my 43 in the lead (put getting killed on handicap) with 3 NM 41s, 2 morgan 45s, 2 more Peterson 43s and a boat I cannot identify. The competition was great, better than it is today. So maybe the IOR era was not so bad?