My take is, if you are retired, and have plenty of time, then a 6-10 knot speed in pretty much all you need. If you are still working, and need to cram a lot of travel into a small time period (like a weekend) you need speed to do that.
I'd almost reverse this comment. I'm 73 and there is a lot I want to do without being away from home for long periods of time. There's this silly thing called death that guys in there 70's begin to contemplate, not much difference between us and some guy sitting in a Texas death row cell except that guy knows the date better than I do.
As I told my refitter when I first brought the boat to his place, time for me is much like dog years, every one of my years is 7 years for younger guys. So I asked him to "briskly" work on the refit as I wanted time to enjoy it. You'll be happy to know it didn't work. I was 70 when I brought him the boat and 72 when I got the boat back. And in that length of time, I lost a very good buddy to pancreatic cancer, a Chicago roommate (university) who had come up once to cruise my waters, hoped to come again, but didn't make it. In our 70's we are living in dog years.
I've had some guys say well when you are doing 22 knots you just aren't enjoying the scenery, too much happening too fast. I say to them, get in your car and drive from Chicago to Seattle at 25 mph and let me know if the scenery past by too fast.
Boating evolves like everything else. The boat show in the 70's was mostly sailboats, the boat show in the 2020's is definitely more power boats. If I had said to a guy 35 years ago what the boating world really needs is a fast trawler, he would have said, say what? If you have deep pockets, maybe that's what you should be looking at - a fast trawler.
Express cruisers aren't considered as cool as other types of boats so you get the Tugs that plane (what?), Trawlers that go fast (what?). To me the Tugs and trawlers that go fast are really express and sedan cruisers in drag.
Even if a hundred guys here say they made the transition to slow with no problems, you could be the hundred and one guy who didn't like it. As others have suggested you might try a charter, go out for a couple of weeks and see if you and your wife like it.