If your mileage is low the the sports tyre is the better option as the tyre will wear out before it is out of date for safety.
This was the reason I tried my latest 2 sets of sport tyres, Bridgestone S20 and S22.
Awesome tyres, but both squared off the rear and wore the sides on the front rather soon.
Could also be something to do with they having front dual compound perhaps.
Only fault I had the the SportsTouring tyres was that I seem to have been regularly to the edge of the tyre without trying too hard, but on the Sports yre I do not get to the edge unless I am really pushing it..
May be true in general, but better to check case by case.
I was able to reach the edge of the S22 rather easily, but there is absolutely no way I can do the same on the Road 5, even leaning more, and both rears in the original 180/55 size.
I don't understand why Michelin makes the edges almost "vertical" on the rear.
Another point for sport tyres is that they may give more some kind of mental trust that we are on "better" rubber, but after gaining trust with sport touring, it will be essentially all about the feedback the tyre give.
In fact my recent experience, I trust the R5 as much as I did the S22 in road sport riding, and even more if it's damp or wet.