Length still matters.
I have a 9.5" Ruger RH and a Rossi 92, both in 454 Casull. I have them for flying in Alaska. I carry the Ruger RH in a shoulder holster accross the front of my chest mostly because if I am stuck in the aircrafts cabin after a crash it can be reachable if I'm injured. In the back of the plane is the Rossi 92 with a Leupold VXII scout scope on it. I use the Hornady 240 gr. Mags. Since weight & flying are an issue, often they both can't come along, and since anything I take must be able of also pulling hunting duty, I need something that's accurate at range.
I have shot the 7" version and it's okay, but if you need 1. accuracy 2. at range and 3. an ultra hot round impact for dangerous preditor protection (pure, raw, unadulterated power, then the longer barrel is requisite and it makes a difference.
I kinda snickered at the Alaskan when it first came out. I carry the 9.5" Ruger all the time all day when Dangerous preditors/angry moose are a possibility and drawing it quickly from a cross-chest holstered position is not a problem---and mine is scoped, so I don't understand the Alaskan. Carrying for protection against humans vs D.P. is two entirely different things. You dress different and do different when you have to work/ accomplish and carry. I'm always climbing in and out of the plane loading and unloading, so I just can't have something on my hip or back that is catching and snagging. I also have to be able to reach it with a lot of clothing on, and my setup goes right under my Carhart vest. Cross chest is the only thing that works for me. After decades of being in remote AK, I find the bear behind the bush that comes magically out of nowhere like a panther to be a myth. You can stumble upon a situation, but never so close that the Alaskans shortness would be of benefit. You need the barrel length to produce the velocity and accuracy as for instance, a 2" 357 (snub) is roughly equivalent to a 4" 9mm in energy and the 9mm would be more accurate. Therefore I'd take a 1911 or 6" 357 revolver over an Alaskan in Alaska --- and nobody can shoot an Alaskan fast due to its kick and kick does not directly equate to velocity. I'm sorry, but I see the Alaskan as a pure novelty just like the Rossi Ranch Hand mare's-leg is.
It is not my intent to rain on the novelty of the Alaskan, and I certainly do not want to offend, as I just want to make it clear since it could be a life altering mistake for a novice to think that the Alaskan is suitable for Alaska, as it would be on the bottom of my list when my life is at stake.
Lastly, never forget hand placement with a Casull revolver as the cylinder gap is dangerous to the digits. I say this because the extreem kick causes people to hold funny.