I love them on my 9mm upper and 7.5 upper . The only ones that are the correct height for standard AR platform are the Centurion Arms set
Problem is they have long been discontinued so very hard to find
There ones that are readily available ( OEM HK brand ones are made for the HK416 / 417 ) . Problem with those is the height is not correct for std AR , since the HK has higher rail height for the piston system
See pic below that illustrates that . The difference is annoying enough that if its your main sight, its not really workable . As a back up, I guess you can live with that
Lastly, for SBR or 9mm applications, you should change the drum over to the MP5 drum
So, to finally answer your question , IMO they are awesome for close range using the MP5 rear to give you the very fast ghost ring style sight ( the MP5 drum aperture is huge ! ) . For reaching out further more precision shooting, I prefer the sight picture form the Troy rear / HK style front or similar sights . I personally don't like the V notch setting, but know people who love it