I used a Rollei for years before I could afford a 35mm SLR, and before that a Speed and Crown Graflex.
You develop a way of working with any equipment, and found I would work as quickly as I required with practice. I photographed sports with both of these.
I even used to reload my Rollei while still on a flash bracket by releasing the back and turning he camera up, being extra careful not to torque the back or drop the film.
I found the C220 and later the C330s to offer quicker loading while photographing a job, and yes, 220 film was a great comfort while shooting an event.
Your composition and Viewfinder experience is different, with your angle of view lower. I find this difference in perspective something I want in some situations.
And, the smaller enlargement factor can yield a contact print like quality. I used to think there was an actual difference in the tonal range I could get out of MF negatives, but I could never quantify it. The film base is clearer, but no one seemed to think that had any effect on the way the negatives print.
Finally, I sometimes like the square format, and other times I did not have to worry about horizontal or vertical cropping and left that to the darkroom to decide.
The Mamiya cameras produced fine results, the 105 mm was not an expensive lens, but it is neither fish nor fowl, a length you might not use very often. I have a wider lens, 50 or 55mm? which is very good working in tight quarters, I do not think the 65 wide enough relative to the 80mm normal.
With the prices generally very low, I would try to find the C330s, the last model, and probably not too much more than the rest. The interchangeable screens were different in the C330f and C330s, I really needed the split image screen. The footage scales on the Mamiyas are not much use for zone focusing.
The Rollei is more of a street / travel camera, as it is lighter and smaller. The Yashica 124G was OK, but you should be able to find a Rollei for close to the same price with some effort.
Which reminds me, I should be selling much of what I have sitting about. ;-)
Regards, John