They make good beer but they're hard to clean.
We used to clean the inside of the vessels with phosphoric acid cleaner strong enough to cause third degree burns on contact (ask me how I know that).
The outside was cleaned with wort with sulphuric acid added (about 5% IIIRC) usually once a week.
If you want to go down the polish and lacquer route: the best and longest lasting I've seen is an Australian made coating called "Like Armour". Not cheap but worth it IMO.