Switching it DAB+ is great. It makes better use of the available spectrum.
Adding in extra stations at the same time is such a shame. The audio quality of commercial DAB stations in the UK is so far from “Crystal clear digital sound” that we were promised.
To build on this good answer, there’s an additional factor: How well a receiver can make use of the signal it receives.
I have both an old and a newish DAB radio. One can decode the audio pretty much anywhere in our home. The other only has stable reception if I put it by the window. It’s the same signal, but it’s not strong enough for the old DAB radio in most places at home.
Edit: This may be true for different FM radios too, but less noticeable as FM doesn’t have a “digital cliff” where the decoding just fails as
seenheard on DAB. Plus, DAB is comparatively new technology… Oldish FM radios still have decades of techy wisdom in their design, whereas as of today, old DAB radios haven’t had the benefit of time for the engineers to optimise their design.