the truth/opinions about cams

Seems theres always a cam question. The answer id like to find out is when a statement is made about newer grinds vs old if both were compared on a dyno would there really be a big difference?Would it be worth the change? Are we talking 50 hp diff. if comparing same .050 durations similar lift same lobe centerline but newer profiles? My guess is no ,but id like some opinions,remember same #s just old vs new.Another pet peeve is mfgrs, comp vs crane vs racer brown vs lunati and so on (because they must be using chevy lobes) how much power is it and is it worth to change ? Another is put on some 1.6 vs 1.5 rockers on a .450 lift cam and look out for that extra 50 horses. NOT! If you took a factory stick like the 340 cam and had one ground with the same advertised .050 no matter the grinders you will probably gain at least 1000 more hp. Right!
just rambling