A 7.5 lb rifle chambered in a standard cartridge and a magnum weighing .5-.75 more is like peas and carrots.
I want a critter hitter and not a sprayer and prayer. With that said I haven't ever been able to shoot a ultra lightweight rifle as good as one of moderate weight and honestly a 8lb gun has never bothered me while hunting in the mountains.
I am sure guys will chime in saying they can shoot 6lbs guns very well, and maybe they can. I can not and a guy has to know his limitations.