In that price range there doesn't actually seem to be a huge number of 8x42s to chose between atm (which could have its advantages
). In addition to the RSPB models there's the top models from Opticron :
and the Vortex Viper HD :
There are a few more 8x30s (including the venerable Nikon EII) and several IS models.
When I first saw the original post and typed RSPB HDX 8x42 into Google I found this thread started by sedgemoor which quite enjoyed reading :
Yet another illustration of how important it is spend "hands-on" time deciding (which it seems the RSPB shop is generous in allowing).
Good tip from dipped to make sure the RSPB HD model is also checked out if haven't done so.