We've used the Tommee Tippee Closer to Nature range of bottles since a few weeks after our twins were born, and have found them to be great.
On a recent trip we accidentally melted our 4-bottle steam sterilizer by resting it on an electric hob! (Not a great plan!) So we bought this thinking that it was a 4-bottle sterilizer.
While it only takes one bottle at a time, it's a very handy accessory that really doesn't take up much space, especially on short trips to visit friends and family.
That said, with twins, it does take up more time (which we don't really have much of) so quickly bought the matching 4-bottle sterilizer.