Just my 2 cents...it depends in my opinion on what the primary use of the gun is. If it's going to be a primary hunter and not a back up...I like the longer barrel lengths. If it's a back-up, a 4 or 5 inch is a bit easier to carry or less cumbersome I suppose for ME. For example, I have 2 SW 29s, a 6" for hunting because I like the longer site radius and a 4" as a backup for when I'm woods walking, hog hunting with a single shot or black bear hunting as it's easier to carry than toting a rifle in and out the truck or if we're searching for a wounded bear or whatever..just some examples off the top of my head.
So....my suggestion to you...there really isn't a spits worth of practical difference between the two...pick each up, close your eyes, bring each up to eye level, open your eyes and see how each feels. I carry them on my belt strong side...I use an uncle mikes, cheapo holster for the 6" and it works just fine. It's not a high ride, I'm too short for one of those and I'm not all all concerned with concealability. I use a bianchi, camo accumold for the 4" and it's fine, though I think I'll look for a holster the pulls the butt in more (like an askins avenger) to make it easier to climb into tree stands, have under my coat or jacket, climb into and out of trucks, etc.
Hope this helps.