Just be aware that they are completely different guns.
It comes down to do you want that classic, recoil operated design, or a newly designed, camo-covered gun?
An older Auto-5 will give you pleasing, historical looks with old-time craftsmanship. However, you may also have a fixed choke, with limited ammunition options. The older, Belgian made guns were not designed for steel shot.
The Japanese made Auto-5 is rated for steel I believe, and later models have screw-in chokes.
A "new" Browning Auto-5 gives you modern steel, lightweight components, a durable camo finish, screw-in choke tubes, ability to use all sorts of modern ammo and I think they have a 3 1/2" version.
Any of them will give you lots of enjoyment. Buy what you want.