Some thoughts from a current owner -
1) The fine is a European Fine so it's going to be a lot thicker than you may expect. If you normally go with a medium or a broad, you may want to consider stopping down a notch or two here depending on your taste. Just don't go in thinking it's going to write like your fine/extra fine Pilot Metropolitan and you'll be good to go.
2) This is a #5 nib, not a #6 as I've seen floated around before. In theory, you should be able to replace it with your nib of choice, but I had issues getting the cap to close when I did. Replacement nibs can be had for $15 a pop from the Levenger site and they're the same units used in the Levenger TrueWriters.
3) It writes well and with a good nib it's as smooth as I'd expect for a fine, but is very wet. If you're like me and you're cool with that, you already know how important paper choice is going to be here. If not, or you're not sure, you'll want to be open to trying different inks and paper combos to get it where you want.
4) Speaking of the nib, there are a few concerns. Quality issues has been my personal experience with my first unit having issues with hard starts and skipping. Replacing it solved the problem, but also exposed what others have said about it: the black is a coating and it will chip on you. Within a few weeks of regular use, it was showing on both the bad nib and the replacement (current) nib.
5) This goes into how I know about the cost of the replacement nibs. When I tired to report issues, it basically came down to "Sorry, but you didn't buy this from us directly, so take it up with your seller." Which, if I'm being honest, is understandable. So I returned it, got one from them directly, and it had the same problem. This is where I screwed up and tried to fix the nib myself, bent it, and had to buy my own. :P
6) The grip isn't as slick as I expected (since it's metal), but I find my fingers travel quite a bit over longer writing sessions.
7) After a few months of ownership, I do notice that the trim on the cap where it says "Levenger" is starting to wear down. It looks like the gunmetal color, like the black parts of the nib, is just a coating.
8) I really do like the weight of this thing. It's not so heavy to be a distraction, but I do feel like I'm holding a hefty chunk of metal in my hand (Unlike the Tombow Zoom 101 which feels super cheap for a carbon fiber fountain pen). The body feels like quality in the hand.
9) Here's a poorly lit photo of my poorly done handwriting on Code&Quill's Origin notebook (100gsm).