I'm a bit late to this conversation but let me add a bit.
I bought the Alaskan in .375R a couple of years ago when I found one dirt cheap on GB. It shoots very well with factory ammo. It shot the 250gr GMX best of all with groups consistently under an inch and right about an inch with the 270gr and 300gr.
Once I got to Africa my buddies talked me into putting a suppressor on it and for some reason the 300gr no longer grouped well but the 270gr did so that's what I shot.
With the exception of the Blue and Black Wildebeest and my Kudu all of the bigger animals I shot I took with it.
The only animals that required a follow up shot at all were the two zebra I took while the Sable, Nyala, and Waterbuck all fell stone dead with the Sable and Waterbuck both being shot right above the sternum at near perfectly straight on shots.
After we opened up the Zebras it was obvious that neither really needed the follow up. Even the big stud which ran a ways had both lungs and the off shoulder taken out with the first shot which entered at about the last rib and buried up in the far shoulder. It was a fairly long shot with him quartering hard away and after seeing the damage done I really couldn't believe he ran as far as he did. The second shot was just behind the right shoulder and buried up in the opposite shoulder just inches from the first.
Functionally the gun has been excellent and it continues to perform reliably and it will most certainly be making the trip with me when I return to Africa in the next year or two.
As for muzzle brakes I have a great deal of experience with them. The 360 deg radial discharge brakes are all with the exception of the Gentry Quiet Brake very hard on the ears, more so the ears of anyone to your left and right than your own and should never be fired in an enclosed situation like an indoor range or from inside of a hunting blind without extremely good hearing protection.
Personally I like having a brake on my magnum rifles because it just makes them more enjoyable to shoot. It doesn't make much difference if you're only firing one to three shots especially on a hunt but from the bench the recoil reduction really makes a difference over the course of many rounds fired in a single sitting.
After trying a dozen or more different makes of brake over the years I came across the North West Precision muzzle brake (slotted version) and now have them on 8 different rifles with another on the way right now.
http://www.ebay.com/itm/221311913421?_trksid=p2055119.m1438.l2649&var=520190416845&ssPageName=STRK:MEBIDX:IT
Even more important than the noise from the radial brakes is the fact that if you are shooting prone or in show/ice covered foliage the blast will fill your eyes with debris and can blind you so you can't see the impact of your bullet and the possibility of eye damage is fairly high from them.
Even without the brake though I didn't find the recoil to be terrible and unless you are particularly recoil sensitive or have underlying neck/shoulder problems it's not a big deal.
Personally I'd send the factory brake to NWP marking the 12:00 index point and have them make one for you.