I now have a few S&W 627s and both a 686P and a 66 - and I am not so fond of 'real' .357 Magnums. I bought mine new, so they were tested with 'real' .357 Magnums. I reload, so I load wimpy .357 Magnums - .38 Specials in the .357 Magnum cases. Why? I like the confidence it will shoot .38 Specials - even +P's - all day long. And also, because I have never seen a seven or eight shot .38 Special! I did discover .38's late in life - some 11.5 yr ago - long after .45 ACP/Colt and .454C - then .44 Special/Russian/Magnum... finally, .38 & .357M.
While I never have bought - or made - a true .357 or .44 Magnum round, I shot hundreds of 'real' .454's - most over 2,000 ft-lb KE. I guess I got the loudenboomer/big kick out of my system, as I traded that .454 SRH over nine years ago (I have the hearing and wrist damage to prove it!). In any case... I now love the .38 Special - and my wimpy .357 Magnum loads. I'd get a .357 Magnum - preferably a S&W - but, by all means, get an adjustable sight! That 3" GP-100 was too far off, no matter the distance. That was too far off for a Vaquero, even! Good luck with your decision... you know, as long as you keep the ammo for later use, trade, etc, you'll have a great outcome!
Stainz