I've been looking mostly at either the model 617 and 817 due to the 7 round capacity. I would like to have the option for the magnum round but am fairly certain I would be more than ok just carrying .38 spc. If I did, is there a significant difference between the .357 M617 and the +p rated M817 firing the .38 spc rounds? I also noticed while looking at specs that the 617 weighs in at about 28 oz and the 817 being about 6 oz less - is this a significant difference for carrying? I am somewhat interested in the ultra light frames, but prefer having some weight to the gun as I'm used to firing an sp01. Thanks for any and all help!