I have damaged a Smith rear sight. Not broken off, just cracked the rear blade. Didn't render the sight unusable by any means. I dropped my 29 on the back bumper of my truck, landing right on the sight.
I for one, have no problems with adjustable sights. I like them.
I'd look for used 686 if thats what you really want, but feel they cost too much. I've seen a bunch of them for $325 to $350 used.
Several Smiths I know won't work (action jobs) on Taurus or Rossi guns, they say nobody wants to pay what it costs to get them up to the same level as a Smith. I don't say this to stir anything up, just reporting what a couple gunsmiths have told me. I have no horse in this race. I see the imported guns selling for what good clean used Smiths go for, and I'd choose a Smith every time. Just me. Your mileage may vary.