I don't find the 9mm hard to wear at all
But my fingers aren't small either. I am a 6, and I have long fingers and just kinda large hands. So I think the size fits my hand with looking "too big". And the stone is about 10mm off my finger, so quite low set for the size of the stone.
The ring does get some attention, but nothing that has made me uncomfortable. I either get the "that is beautiful, what stone is that?" Or the "OMG! is that a pink diamond? It can't be....but is it?" I have gotten the most comments on it at the salon I go to. The lighting is really good in there, and women are generally sitting around with nothing to do other than look at other people's hair and sparkles.
But it is just fun attention...and it leads to conversations about diamond alternatives.