Yep, I'm a cup at a time. Exact same model as @mrk I think. Had it about a year, no problems. I didn't buy it for energy efficiency though, I bought it for speed. I was at my mums last week and it made me realise how annoying waiting a couple of minutes for a kettle to boil is. When you've only got a minute between (virtual) meetings, a cup of boiling water in 30 seconds is very handy.