Hey JWP475 that is a nice rig there Fiber barrel and all but I find walking/hiking at 8500-10,000 ft.lvl my RUM at 8.5 lbs. with a 4.5-14 x44 Zeiss is just comfortable to carry. I think for the average shooter you really can't beat the RUN for performance on game and at the range.
Last time I was at the range I was talking with a guy who was shooting a 338 Lapua. He said that he can't shoot the targets at our range that are 500 yards or less because it tears up the steel so much.
I would think the 338 RUM would be more popular since there is factory rifle chambered in it, but the 338 Lapua is more of a specailty round. Either one sounds like it would just destroy whatever it hit.