I own a 7mm and a 300 WSM. Have shot the 7mm for 25 years and killed a few elk and several mule deer with it. The 7mm does good with 160 gn bullets but starts to loose steam with 175 gn bullets. I like the 300 WSM because it throws the 180 gn bullets very well. The 300 WSM does have drawbacks though, they can have feeding issues due to the short fat case and steep shoulder. As a matter of fact, some people recommend NOT using a 300 WSM for grizzly and such. Also, most rifles hold fewer rounds in 300 WSM.
I have a Savage 12 VLP DBM in 300 WSM. Could not get it to shoot ANY factory ammo well. The thing was like 2 MOA, very discouraging. Then started reloading it with Norma brass, Federal 210m primers, H4350, and 180 accubonds set .005 of the lands and now it is 1/2 MOA! I have 200 rounds thru the Savage and have had absolutely no feeding issues. Only issue I have is that the removable magazine only holds two rounds.
As far as the Sako 300 WSM goes. I have heard that they do not shoot 180 gn bullets very well sometimes because they only have a 11 twist rate. Most standard 300 WSM rifles use a 10 twist rate which allows them to shoot the lighter and heaver bullets. If you search this site and the web you will find the Sako twist rate issue discussed a lot.
Only bad thing I can say about the 300 WM is that belted magnum cases can be a little more difficult to deal with when reloading. Most people don't get as many reloads from a case due to various issues with the belt. This is why I love my 300 WSM. The 300 WSM is belt-less and does not have these issues
I would look into the Sako twist rate issue a little closer, if I was going to get one. Love the look and feel of them and would be a much better carry gun than my Savage.
Everyone is right about the weight. The Savage 12, like the Sendero, is about 12 lbs. dressed out. I would try to get something more like 8.5 to 9 lb. dressed out, if hiking with it.
For recoil. I feel that is not enough difference between the 7mm, 300 WSM, and 300 WM to really worry about. If you can shoot one you can shoot the others. I would try not to make a decision based on recoil, but would not get some super light weight mountain rifle in any of them.