Very nice. I am extremely fond of ~50mm lenses; many years ago after "graduating" from my first MF SLR which only had a 50mm, I wouldn't think of using a "standard" lens; but after acquiring an old Leica and only being able to afford that 1 50mm Leica lens for some time, I realized that it really is a lovely FL. I totally fell in love with 50's again.
I think the Q's 50 is quite good. I don't like it as much as my Summilux, but I like it better than many 50's I've owned, and I think it has a very nice way of rendering. In particular, it draws light quite well; much less macro-contrast than many modern lenses which seem to be so heavy handed to me. In many ways its micro-contrast is more Leica-like than most modern lenses. And it has great bokeh, in my opinion, if you're into that sort of thing. Of course DoF isn't as slim as I'm used to, but it's slim enough to have a nice "pop" to your subject in many cases. What a treat for a "free" (ish) kit lens.
To be honest--if a wide prime of equal quality comes out, and a "portrait" tele, this little camera system will really get my attention.
My Q actually isn't "mine," either. I bought it for my wife. But I can't seem to put it down.
Re: grain. I really like the grain from this sensor, also. To me, turning NR to "LOW" and "Fine Sharpness +1" or +2 brings this out nicely.