I fell in love with the Pilot 78G+ clear from YouTube videos, and it is equally impressive in my hand. I was waffling between buying it or an almost half as expensive Wing Sung 659 (which is a clone of the 78G). I decided against the 659 because of the threads at the top end of the cap, which ironically it turns out the 78G+ also has. Not a coincidence, since the 659 is a copy.
I didn't mind the Con-40 at all, but I habitually filled it with a syringe the first time, so I never learned the horrors of filling it normally. And there was no second time, since then I threw it away in favor of eyedroppering. I used silicone grease but no o-rings. No leaks.
In the photo, the pen is feed up, of course. I've replaced the Pilot feed with a transparent feed. It's catching the light just right, and actually often just looks black - or clear.
You can see in the writing samples that eyedroppering makes it modestly wetter, but the generic transparent feed makes it write much dryer/thinner, close to the Wing Sung 698 0.5mm "F". I think this is the reason that the Wing Sung 659/698 0.5mm nibs are labeled "F", whereas low end Pilot 0.5mm nibs are labeled "M", even though they are reportedly made on the same machinery. I'll know for sure when I try a Wing Sung feed in the 78G+.
This 0.5mm nib writes very, very smoothly, of course. You really have to think twice before buying a fountain pen other than a low end Pilot or Wing Sung 698. Pilot claims these nibs are 22K gold plated, and I believe them, as opposed to laughing off whatever the Chinese claim. The gold plating isn't going to do much for you except for looks, of course.
The main disadvantage of the 78G+ is its light weight. It is just 13g, either empty with converter or full as an eyedropper. I really notice the difference in weight between it and the similarly sized Moonman S1, which is not exactly heavy at 18g eyedroppered. (The S1 and 78G+ make a dashing pair, by the way.) I considered adding titanium, but first I'll try glass beads, which are on the way. The other thing I'm hoping from the glass beads is that they'll lighten my dark colors enough that I can see the color easily in the barrel.
I don't mind the lack of an inner cap. That eyedroppered pen is my daily carry in temperature extremes, and the cap stays clean. Actually, I prefer no inner cap. Having no inner cap definitely looks better with this demonstrator.
The ink is a 50-50 mix of Sailor Storia Balloon Green and De Atramentis Document Urban Grey.