A mixture of both but with a bias towards stormy. Can go from glorious sunshine to horizontal snow in a minute or less then back to glorious just as fast! Plenty of the sights are photogenic even with flat light, although the horizontal snow was a little more challenging... Take a flask of coffee and sit in the car waiting for a break in the weather, chances are that it won't take too long.
If you visit the ice beach, head a couple of hundred metres East of the café turn off and look for a small roped off area on the seaward side of the road. Earlier this month there was a run off gully down to (and, more importantly, up from!) a relatively deserted area of the ice beach with plenty of 'bergs around. Get low and you'll be able to hide the hordes of other photographers behind the blocks of ice. Beware (VERY aware!) of the sea conditions, the occasional wave will come up a lot further than the others and will fill your boots (if you're Paul) or the splash might get into an expensive lens (Richie). Make sure you have an escape route planned. Oh, the tops of the ice blocks are slippery but the sand gives plenty of traction on them if you lob a couple of handfuls where you'll be planting your feet. A few km west of the main ice lagoon (8km or so), there's another turn off up to an almost deserted and just as spectacular ice lake that doesn't shed into the sea. Further West, there's a place called Svinafellsjokull where you can get much closer to the tail of a glacier.