Many of the high moorland 'circles of Britain, where the stones barely break the surface, make it abundantly clear these were purely functional sites, the builders in awe of their surroundings and making no attempt to compete with nature. Castlerigg may be a photographer's wet dream, but I think, for example, the Burn Moor 'circles are actually the real deal instead.
To answer the 'upon arrival' bit, my first thoughts are often... 'is that it? stones aren't that high etc..' But first impressions, in my experience, are often very mis-leading.... just scratching the surface. My average visit time, I'd say, is about three hours.. sometimes longer if the vibe is really there, sometimes shorter if access is an issue. But I find it takes a while for the relationship to the landscape to become apparent, to try to understand why the monument was placed where it is. Very often the attention to detail with regards placement is astonishing, almost as if the form of the site is very much of secondary importance to where it is. Dunno, but in my view if you don't take the time to sit, look, absorb and think, you may as well be collecting stamps for all the insight you'll get. Less is most definately more.