I use a 3 speed S-A for road riding.
It is smooth, silent, light, nicely made, and reliable. It has over 100 years of development.
I also own a few other hubs:
Nexus/Alfine 8 speed
Rohloff
Assorted others, eg Duomatic, S-A 7 speed, S-A 4 speed, the new S-A S3X hub (yet to be fitted), etc.
The Shimano hub is very nice but I prefer the lighter rear wheel you get from the S-A 3speed (the 5 speed is the same weight according to the website), and the only reason I'd use the Shimano is if I desperately needed the wider range – perhaps towing a trailer.
The S-A 8 speed should be avoided unless you are running it on a small wheel commuter, or will spend a lot of thime in low gear because bottom gear is the direct.
The nice thing about the S_A is that the middle gear is direct, thus no drag. Set that as your usual cruising ratio and the other ratios fall nicely into suitable reductions or stepups.