Ash, generally they are worth more than non-take down versions. Holland & Holland also use this method and the argument for is that you do not wear out barrel threads. With modern steels and heat treatment this is not generally a problem and may not have been then either, at least that was the advertising. In theory you are not separating the action from the barrel so accuracy should not be affected providing the stock bedding is good and not damaged. The take down model is actually quick to dis-assemble.

Waidmannsheil.