Omega Speedmaster Reduced. What do you think about this example?

Who did the service? With one of those it’s the condition of the movement, not the crown, pushers and crystal that would worry me. Omega routinely swap out the modular movement at service time. Some other third party repairers service only the time components and leave the chrono module as it is. Some do both and yet more refuse to do these at all. If the chrono module was left alone then it could prove problematic down the road.

Note the service card you show is dated 1995 so I assume you are referring to a more recent service.

ps The 51m serial on the card should be stamped on the outside of the caseback. Check because it’s nowhere else on the watch so if it’s not there, the card is meaningless.

I don't know that repair outfit, are they German or Swiss maybe? Maybe another contributor can offer a testimonial? The paperwork doesn't really give any information regarding what was done so it is difficult to say whether they did a comprehensive job or not. As I say, the majority of aftermarket watchmakers won't disassemble the Dubois Depraz module which sits on top of the ETA 2890 (or 2892) and provides the chrono features. Those guys may have done so or maybe they have not. It would be worth finding out if there are an Omega accredited repair organisation, if so they likely swapped it out and all is well, if not then who knows. Looking at the paperwork though it seems unlikely that they are Omega accredited.

As to the price, well if the service was done properly then it doesn't sound too far over the top. If not then it is overpriced by the cost of a proper service, ie $600-700. It is the service issues that make the Reduced models much less popular than the integrated chronograph movement watches like the Speedy Pro etc and it is the reason you see many of them offered on ebay at tempting prices, since so many need an expensive service.

If they are accredited then you are probably fine, one running right is a nice thing. The issues with compound chronograph watches aren't limited to Omega, many other manufacturers made them (some still do) and all have similar issues. I have had my fair share of issues with DD module watches, some still ongoing and going forward will never touch another.

The case is too overpolished for my liking and I think they also replaced the bezel; but the price considering the service is quite good. Its not a collectible watch so replacement hands and other parts don't really matter, its just personal taste (do you want the lume color to match etc.)
Heres mine from 1995 (selling soon to my good friend 🙁)