I'd agree that the Win 70 Safari Express is muzzle heavy, and I'd also agree that it's personal preference, or in my case situational.
I really liked the balance in my 375 because I was primarily using that rifle as a driven boar / running target competition gun. The front heavy balance was of great benefit to the stability and smoothness of the swing in that situation, giving the gun a bit of inertia and counteracting any minor wobbles during trigger pull. A little harder to get moving in the first place, but a very stable platform after that and if you start swinging during the mount, you have a bit more leverage to start rotation whilst it's held tight to your chest.
It was also quite good for standing or kneeling shots as you could mount then relax down through the point of aim during the trigger pull. Again, the nose heaviness aids stability and stops too much wobble, especially if you do a hasty sling or use a 'Cooper' type sling for some isometric tension.
Sitting, prone, off a bench, it didn't really matter much either way.
However, it was a real detriment to snap shots and quick target acquisition at closer ranges. I found that the simplest method to work around it was to do the shotgun technique of low ready, step into the target, mount and shoot in a single movement so you can get the target acquired whilst the gun is held close to the body. With the scope on 1x and with both eyes open this was quite effective. Still not as quick as something light and more neutrally balanced like my 270 or my Marlin though and it punishes poor footwork or mounting technique heavily.
For a real charge situation, I think that any change in the animals direction of travel whilst you're trying to acquire the target would be a problem.
If you want to try this sort of 'dynamic' shooting assessment yourself, the easiest method I found was to get a laser pointer and a blank wall. Stand a reasonable distance away (say 10-20yds) and get someone to flick on and then move the pointer in varying directions (across the wall = crosser, down the wall = charge, etc) upon your call. Try to get the crosshairs covering the dot as fast as you can testing various methods for mount and swing. Obviously do it with an unloaded gun with the bolt out, but it's an informative exercise.