The 870 has always been a great shotgun, but it's gotten worse in recent years by Remington's poor quality control since Cerberus/Freedom Group took over. That said, the advantage to the 870 is that it's a shotgun, and tolerances are loose, much like an AK. As such, variances in production quality make little difference for general operation.
All of our tactical Wilson Combat shotguns have those sights. They're excellent for long range shots; particularly with slugs. I don't like it for rapid shots, and I would actually prefer a bead sight for close range work, but if you spend enough time with the Wilson sights, you can get a bit faster.