Yeah, I've been here just under a year and only had the 550 about 19 months, but IMHO:
I think DonR "hit the nail". These bikes made every other bike mfg sit up and notice - then they had to improve their product/s ASAP playing "catch-up". Honda had already "hit the ground running" and had the other mfg's chasing their tails!
Also, Honda built 'em to last. Otherwise, there wouldn't still be so many of 'em still up and going and we couldn't be still riding 'em. (And, without this great Forum, a LOT of us wouldn't be riding 'em because we wouldn't know how to fix 'em!)
They're not the only bike to own/ride by any stretch. But, they are a great, successful over-all design, powerful enough for most sane folks, dependable, unique, vintage and fun to ride.
Why look any further?!!!