Well I shot the Codnor HFT today with the Mamba on top of my GML 400 and I really liked it.Its not any clearer than my Japanese Tasco, as I kept checking the one on my daughters gun at different targets to compare.

But it did seem to have a bigger sight picture and the real bonus is the reticle.
I did drop one shot though when I didnt realise that I was using the centre cross in stead of the first full horizontal for 45 yards,silly mistake that I might have done with my old scope.
Overall I think its a keeper,I dont think you will get better glass unless it is top end european or very high quality Japanese,and then you'll be hard pushed to see a major difference,and to be honest I dont want £500 scopes on my gun really.
I think the only other scope that I would consider other than a Mamba is the Lightstream FFP and they are nearly double new price.

So Its a good scope all round and I agree with everything Armbands has said.