Sorry bout the GSR/GRS spelling. Natman I know what you mean and yes shooting a peep or GRS you only focus on the target and front sight, no rear sight to line up. Peep sights offer accurate and precise shooting. If you train with a GRS I'm sure you will be fast and accurate. My opinion is based on my own experience. I find it easier to negotiate a home without a GRS. I also don't like lasers on handgun but many people use them with ease and swear by them.
As I've said before, there's plenty of room for personal preference. If you understand how GRS work and you've tried them but based on your actual experience find something else works better for you
, then by all means go with what works best for you and Godspeed.