Having owned and currently owning various new and old iterations of the High Wall single shot, the ergonomics are similar and net results are the same amongst them all. Downside to the Browning/Miroku B-78: lousy trigger (since corrected in later Miroku-built versions), garish wood finish and glossy bluing that is loved by some hated by others, barrels that are generally lighter weight than original HW's (a benefit for hunters, less so for purely target shooters). Advantages: every one I've ever owned was stunningly accurate, YMMV. Fit and finish is superb, as is the bank vault feel to the action. Stronger than hell.
In short, the B-78 is a pretty dammed good rifle. I would snag it! Just don't directly compare it to a vintage Winchester HW, apples&oranges. There's just something about a 120 year old HW that a B-78 won't have for another 70 years!
