It would be good to think that Browning may have impoved the adjustable comb if there was problems with it. I suspect that a few people would have brought it to their attention.
Speaking of the Citori Plus, they did have a very claen used one in the same shop, at almost $1000 less then the new XT. I liked the Plus as it had the adjustable rib. I can't remember for the life of me whether it had the adjustable comb or not. Would that have been stock with the Plus, or an option? It felt heavier then the XT, but the balance was good. I should have checked to see if it had the invector plus chokes in it. I like the idea of a backbored barrel. Either way it might be a good investment. Save the taxes on the $1000 as well!