I think one of the main issues for me is that it is second best to a 5839 linked system. Obviously there are cost implications with installing a linked system, but you can not get away from the fact that these closures are only as good as the systems and safety culture within the premises, leaving them wide open to human factors, such as poor / no testing being carried out, batteries not being changed on a regular basis.
I have also known instances where they have been prone to false release and as a consequence doors have been wedged open.
I guess what I am trying to say is that you can assess all you like and make recomendations, however they are open to problems that are difficult to manage.
On the other hand if you are completley sure that the above factors can be managed and you have carried out sufficient testing and assessment of the placement of the dorgards, then, as I say, in balance they are not all bad.