I own and shoot a beautiful turn of the century Richard Ellis and Son English hammer gun. The gun is sleeved to the highest order. Balance is perfect and it shoots true.
The fact that the gun is sleeved allows me on my limited budget a chance to own and shoot such a gun. Had it had the original barrels in perfect condition it would have been out of my reach.
I also have a Daintith. again English and around the same date which has stunning woodwork and engraving. Also has cosmetically beautiful Damascus barrels which are terrible in the bores. Tight on the face but obviously out of proof. I would love to have it sleeved but the the gun is not worth the expense and half it's beauty is its useless barrels.