Love mine. Bronze version. Buy again? Yes.
The cap mechanism is out of this world, I'm a teacher (primary school) and capping/uncapping happens about every minute for me (seriously) when I'm in the classroom, and several times a minute during peak times (special needs class, you don't leave a nib exposed for long, anything can happen at any time...)
Nib, 23K Medium, great. Super smooth and wet. If I need a finer line it reverse writes beautifully, and very smoothly (albeit with a small sweet spot). Springy, wipe it on the page and there will be a ink shed.
Materials, bronze lovely, develops great patina. Lava/rubber, fantastic to hold and use - 9 hour meeting is my record so far with almost continuous note taking, very happy hand at the end (don't go there...)
Nib and feed removable, from both pen and then from collar/each-other for full cleaning. BUT I've water rinsed using the vac mechanism three separate times now, then pulled the nib and feed, never has there been even a hint of ink between the two...on my example at least there appears to be no point in a complete strip-down clean. Maybe with some inks, or if left to fossilize, but that's not my style.
Clip, one hand operating is easy once you figure out the "Visconti squeeze", holds well enough in my jacket pocket or on my vest.
Vac mechanism is smooth and consistent.
Section is very comfortable
Size allows for different grip positions, I hold mine a fair way back (off the section in fact) and wipe the letters onto the page, and all this with pretty big hands (over 8 inches, measured the normal way). I do like to post, but with this pen holding the cap in the other hand feels...good, natural.
Clip has Visconti printed on. At this price point ...no laser etching...really? BUT, who knows what the pen cost to make, it's not like any of us have sunk the man-hours into R&D. On the up side once the paint rubs off there will be no banner branding on the pen, making it better IMHO.
When I got mine (second hand) the piston rod had ink on it, ink that had made it's way past the rear seal. There was no leak to speak of, I just worry about the vacuum...mind you the pen fills fine, so I may be worrying about nothing.
Nib is very soft, which is only an issue for me when when reassembling after a complete strip down (see comments above, this may never happen again). the problem being that very slight alignment changes between nib and feed are magnified dramatically in tine alignment. A few slight wiggles of either nib or feed is enough to sort this out. This is more of a warning not to reassemble, notice tine alignment issues and then start bending etc to try and correct. Just wiggle it, just a little bit.
Mine is an early example and needs to be sent in for the section operation (re. fitting of a sleeve) HOWEVER, what does it say about how much I love this pen that MR Cheap-ass here is actually looking forward to having this done, and getting my little Precious back...? ALSO, from what I understand this will be free, but postage is up in the air. Pretty good customer service if you ask me. Many complaints in Web-world about a $3-4-5-600 pen needing to have this done. Suck it up (vac filler joke), this is a new material and early adopters, like early adopters of any technology, should expect there to be small issues. As I understand the issue was soon corrected on all pens leaving the factory, so a non-issue if buying new.
:? Size, everyone says it's big, I don't think it's that big. A Wing Sung 590 is substantially bigger.
:? Wetness re. using the pen on dodgy paper. Yes, this can be an issue. HOWEVER, reverse writing on really bad paper is perfectly fine. N's Apache Sunset and Dragon's Napalm both behave VERY well in this pen and I get no show-through on almost all papers at school (some student books are pretty nasty, I reverse write my annotations in them). This is all with a medium nib, I would really like to try a fine or extra fine nib in this pen...then again the medium is very expressive when you want it to be...hmmm...
:? No ink window. WELLLLLLL......my motorbike doesn't have a fuel gauge, but I know roughly how many kilometers I'll get from a tank. Same with this pen. Trust the fill and guesstimate refill times. OR commit to an ink in it and just refill at the end of every day. My EDC is this pen and a Rotring 600 mechanical pencil. The pen occasionally changes (but not often), the pencil doesn't. It's the ultimate fail-safe. So I'm never worried.
:? Section staining...it's weird. With some inks yes, with others no. BUT with all staining it only lasts a day or so then it's gone...maybe the material sucks it up? Either way I don't care. I use my pens, I don't collect them. I can't wait for my (currently imaginary as my daughter is only 8 months old) grandson to receive this pen, all beaten up and gnarly...and to love it as much as I do/did. Then again maybe my daughter will be a writer with big hands, if so the pen is hers!