Went for a Valentine’s day long weekend a few years ago. An excellent place. We walked around Reykjavik, took a coach trip to see volcanic activity and the original parliament, and spent the evening in the Blue Lagoon – touristy but great fun!
Friends went for two weeks last year in the summer and toured the island and glaciers. You won’t have time for that. Don’t expect to see the Northern Lights, unless you travel far north – only a small island at the top is inside the total day/night latitude. It’s a day away at least.
Go, you’ll love it. Just don’t expect to get drunk, alcohol is unbelievably expensive. And remove silver jewellery as the hot water is highly sulphurous (but free).