Not having iron sights on a rifle is the mark of a serious optimist. I, on the other hand, am able to claim Mr. Murphy as a dependent...he lives in my pocket most days. A few weeks ago I was shooting in a competition and after several misses at 100 yards I knew there was a problem with the optics, I was able to dump the scope which was on a QD mount in a matter of seconds and finish with the irons. I also dislike the clamp on BUIS type of sights...I want something that can be smacked into a wall corner or the frame of a car door and still be dead on. My solution is to always start with a carrying handle rifle and have the carrying handle shaved and a flat top type mount added. This way I have the low flat top scope mount plus the absolute strongest iron sights possible. If you factor in the cost of BUIS doing it this way is likely cheaper than buying good sights for a flattop. Plus carrying handle guns on the secondary market are often discounted because everyone wants a flattop!
Here is my solution...might not work for everybody but the smith who did mine (and there are quite a few who do this including JD Jones) says it is a common mod among both professionals and competitors.
I tend to be a minimalist when it comes to accessories, the less that you hang on a gun the less there is to go wrong. The only thing other than a scope I would ever consider is a tactical light and I still have never hung one of those from a rifle...but I might some day.