Tried JoomlaXplorer and NinjaExplorer but they all had their problems.
Installed OSE FileManager and it worked out of the box but not without an issue; it allowed file and folder access for all sites on the same server - this was a complete show stopper and would have likely led to it being uninstalled and a negative review left.
However I am happy to report that the good people at OSE were quick to respond to my support query and resolved the matter in one hit - superb.
A zero star review became and excellent 5 star review through their quick response and keen willing to resolve the problem. Superb!!
Currently using it when creating a website for a friend who is a photographer and as it is very flexible it means that we can display his images in various styles
Would certainly recommend to others and something I will use in other websites