Hi Mick,
I picked one up awhile ago, and I was pleasantly surprised. While it's not quite Tamiya quality in terms of detail, it certainly has a Tamiya look and feel to the molding.
The kit actually represents Aurora after she was given to the Chinese Nationalist government after WW2. I've not done any research on her, but it appears that she carried the same configuration as late war Arethusas.
The main problem I foresee is the lack of photoetched parts in 1/300 scale. I'm thinking that maybe (somewhere) someone has done some 1/350 rails that might be on the large side, so I'd use those...
This will be very pretty if you back-date her and put her into an Admirality disruptive scheme.
I'd say go for it, like you mentioned, kits of RN cruisers are few and far between.
Jeff