One of the main benefits of reupholstery over loose covers is the ability to retain special features.
Show wood is a good example. A couple of recent examples from the Plumbs reupholstery workrooms are shown here.
In both cases the customers had chosen reupholstery to retain the wood features of the furniture:
The example below shows half way through and then the finished article.
This shows work in progress as the reupholstery fabric is attached beneath the position of the arm:
The finished article looks superb. Every details of the furniture is exactly as in the original state when the furniture was brand new.
In summary for chairs with special features such as show wood, furniture reupholstery is the best option.