I believe sleeved guns are just great, basically new bbls, fit for a lifetime or more.
It also lets you into a much nicer Gun, for the cash you have, assuming its a real good job, & that your ok with that.
My WW Greener 1901 Hammer has sleeved bbls, but no one ever new, unless i pointed out the incredibly hard to see joints, all properly marked n proofed..( or is it proved?)
I see them as a way to get a real bargain, sometimes.
For the collector, no, but a guy looking for a real nice shooting gun, yes.
The balance thing is daft,...as said before,how does anyone know how a gun balanced before the bbls were lopped off...you cant....pick it up n see how it feels for you...then make your decision.
Westley Richards did some really ugly sleeving.....which I find hard to believe, considering their reputation as fine gun makers
best to you all
franc