Thanks for all of the responses and critiques everyone.
In terms of equipment used/how I processed it: it was Canon 7d + Sigma 30mm with a Hitech ND 1.2 reverse grad. It is a stitch job - 3 photos. For each photo I took 3 exposures and manually blended (mainly with luminosity masks) - to get a little more detail in the rock and in order to get the sunburst.
I see the haloing - that was probably partly because of the filter, and partly because of some poor masking as I blended. I have fixed that in a new process. From my own technical critique I don't really like the banding in the sky, and I might try and fix that in another edit, but I may have to reblend them from scratch which is a bit of work
In terms of the 'unrealistic' portrayal of the scene with the bright foreground and backlit scene I completely understand. And I can see that it is not everyone's cup of tea. I wanted to get that sort of look because there are many photos around from that viewpoint at sunset that do look more natural and 'silhouettey'. And those are great photos, but I wanted to try to capture/create something a bit different.
I guess later on when I have some time I might come back to it and process it in a different way; I have plenty of decent RAW data available, but aside from the haloing and banding in the sky I am reasonably happy with how it turned out at the moment.