The answers to these questions will involve opinion rather than fact. Although most here probably like thicker leathers, for me Firenze leather is better as it is thinner and more versatile for every day wear. It's 2.5oz as compared to 3-3.5 oz for Vanson competition weight leather. Unless you ride a bike, you simply don't need thick leather. I find 2.5 oz pretty heavy as it is. Remember also that thick leather does not provide warmth in the very cold as warmth comes from the lining choice or what you wear underneath the jacket. Leather of itself is really just a heavy wind blocker. Older vintage jackets were usually around 2.5 oz and have lasted many decades. As to Schott versus Vanson, models vary but I'd say they are similar in quality. Both products are made on production lines in small family owned factories. Schott has more prominent marketing. Both brands have loyal followers.
John Lofgren Monkey Boots Shinki Horsebuttt - $1,136 The classic monkey boot silhouette in an incredibly rich Shinki russet horse leather.
Grant Stone Diesel Boot Dark Olive Chromexcel - $395 Goodyear welted, Horween Chromexcel, classic good looks.
Schott 568 Vandals Jacket - $1,250 The classic Perfecto motorcycle jacket, in a very special limited-edition Schott double rider style.