Haven't tried UD day nappies but I can really recommend:
WNNL - sooo absorbent and relatively slim
Flutterby Fluff - absolutely gorgeous (no slots available at the mo though)
Baby Beehinds birth-to-potty bamboo - a bit less flexible than other nappies but the most absorbent fitteds I've ever tried (I think they've stopped selling these new but there are usually some in the classifieds).
I love all of these. Wasn't over-keen on EH though - they were a bit too 'firm' for my liking and not as absorbent as I would have liked. They seem to be really popular though.