I started off in the rando world with a 80s vintage road bike upgraded to brifters and I liked it a lot, then I thought my miyata 1000 with a generator hub and 9 speed downtube shifters would be the cat's meow since it took fenders and wider tires. I don't know what it was about the fit or the crank but I pulled a muscle or something in my calf and DNF'd my first 600K, I ended up buying a used specialized roubaix and I rarely ride either of the vintage bikes anymore. They were fun projects to restore and ride but I found the roubaix to be a better fit for me... somehow I survived my 1200K on 28mm tires and a carbon frame, which has also held up being flown across Canada in a plastic bag. YMMV, of course.