I've probably only played one Par 73 course in my life. And I've played a handful that were Par 69 or Par 68. But generally it's 71 or 72 with an occasional 70 thrown in.
I do not find a 6,600 yard Par 71 course to play any "longer" for me than a 6,600 yard Par 72 course. Same for Par 70. If a course is 6,600 yards long unless it is proportioned in a very unusual (by USA standards) manner there will be a metric buttload of 380-440 yard holes facing me over the course of a round. And those are typically driver, fairway wood then somewhere between a half-swing sand wedge and a full 8-iron for a third shot for me. Par whatever I'm going to like that course a lot better by moving up 500 yards and getting some of those Par 4's down into the 340's and 350's where I can reach them with a 5-iron.
You and I play about the same game, and IMHO, there's NOTHING in golf more boring than playing a "metric buttload" of those holes in a round.
Last spring I was recovering from carpal tunnel surgery, and basically playing one-handed so I moved up to the tees that are ~5700 yards. After a few weeks I started hitting it better and a 2-handicap friend of mine said, "You're playing well enough to move back to the whites."
He was completely clueless about the problems of a 200-yard driver. He plays our home course @ 6433 hitting it about 250-260 off the tee. So I said to him, you're gaining at least 40 yards from me on 14 tee shots, right? And maybe 15 yards a club on four second shots on the fives, and on 18 shots into the green, right?.
He agreed.
So I asked him, "That adds up to almost 1050 yards, do you enjoy playing a 7500-yard course?"
He said, "Hell NO!!"
Well, that's what 6400 yards feels like to me.
FWIW, he played our city tournament this year with one round at Firekeeper, and they played it at about 7500 yards, and he was astounded to have one par five that required THREE wood shots.... I have that happen all the time.
K