I bought this DAB radio to use in the bathroom - i.e. running it on batteries rather than the mains. Sony reckons it will do 9 hours on a set of 4 AA batteries, which is probably fair. But using it for around an hour a day, this is only just over a week. The portable Sony FM radio it was to replace could go for several months on one set of batteries. I tried using rechargeable batteries (2500mAh) and they lasted about 3 hours before needing to be charged. I have had to go back to using my old FM radio due to the hassle of having to recharge batteries twice a week or the expense of buying batteries every week or two.
I read reviews of other DAB radios before buying this and I think this is a common problem with DAB rather than specifically this model. If you plan to use a DAB radio on battery power, I'd recommend waiting a few years for the technology to improve and get less power hungry.
In my opinion, the additional sound quality and variety of stations doesn't warrant the hassle of changing the batteries. I bought it mostly for the additional stations, but to be honest found myself going back to Radio 1 after trying out some of the others (too many adverts and dull presenters). The improved sound quality isn't really something that makes a lot of difference in a bathroom anyway.
All that said, it is a great little radio. Sound quality is very good and it is very easy to use. Running on mains power (adaptor supplied) it can't be faulted.