Good barrel sleeving by competent hands is just that and I have not hesitated to consider having it done when appropriate. When appropriate is when the current barrels are not serviceable and the gun is of the quality to make it worth saving.
I have a fine hammer gun whose sleeving looks good and the balance is excellent. I have little doubt the barrels lost were beyond further use.
I currently have a gun with Kirk Merrington which I have no doubt will be worth the bother.
I do caution anyone wanting to lengthen a gun through sleeving the price of ribs added to that of sleeving makes it a very expensive project. To pursue it requires a truly exceptional gun in need of barrels to consider it. That said you will never make money on the project regardless of gauge.
I accept those who do not desire a sleeved gun as opposed to original barrels as a matter of taste. There are both good and bad examples of sleeving out there.
For me I prefer not to sleeve, but there are times when no options exist except parting out, which I see as a worse act when the gun is quality
