The Remington rifle-style sights stay on the gun more reliably than most of the ghost ring sight setups out there. The Wilson Combat ghost rings, for instance, have a bad habit of falling off the gun.
The key to using the Remington rifle style sights is to use thread locker. My "Humble Pie" 870 is chugging right along, having survived my use and being used as a loaner in every single class I teach. The screws for the rear sight have rusted slightly...which only helps it stay put. Trust me: That gun is not treated gently.
As for "high", they're not high enough to change how I mount the gun. Typical Remington front sights will work with the Aridus CROM which is most certainly not too high.