Although I'm still waiting on the Sailor Fude 40 degree angle bent nib pen, I thought I would share my own personal findings and feelings between the Sailor Fude 55 and the Hero 578 pens I have.
First off, I love the Hero 578. Have from day one; however, it's made of metal and can start feeling heavy in the hand after a period of time. Sometimes my hand will start aching.
The Sailor Fude pens are plastic and much lighter. They are also longer offering the advantage of carrying an extra cartridge right inside the barrel as backup.
NIB: The metal piece on top that you apply to paper to make your marks.
FEED: The plastic "gilled" piece directly under the nib that ink feeds through.
Looking at the Hero nib, I'm estimating it might be about a 40 degree angle. Will be interesting to compare it to the 40 degree Sailor once it gets here.
I find holding the Hero at proper angles is much easier. Just seems more natural to the way I would normally hold a pen.
The Sailor Fude I have to keep adjusting my hand and the angle I'm holding the pen to make any marks. That can be a bit frustrating but I'm sure after a period of time, one could get used to that and it become easier. Just doesn't seem to take the same effort with the Hero.
As you are looking at the nibs and feeds, notice the distance between the edge of the feed and the bend in the nib.
Not sure you can read the small print on the photo easily so I'll share here as well.
The Sailor Fude's nib bends right at the edge of the feed. When applying pressure on paper, the edge of the feed can sometimes make marks as well as the nib on the paper giving a double line especially if you hold the nib horizontal (barrel and pen held horizontal) to achieve it's thickest line mark.
The Hero's bend is further away not causing the same problem.
The plus (or minus depending upon individual and what they prefer) to the 55 degree angle nib is it creates a slightly wider line held horizontal than the Hero nib. Will probably find the same thing with the 55 degree Sailor versus it's 40 degree sister.
The Hero has a longer (and a little fancier) nib but not sure if or how that would make much difference in anything.
The other thing the Hero has the Sailor doesn't........at the very tip of the nib is tiny bead shape. I'm sure there's a reason some do or don't have that, but at this point, I don't know what that reason might be.
UPDATE: Thanks to a good friend, Larry Marshall, I learned what that hard bead of metal is all about on some nib tips. It's called "tipping" and used to make the rounded nib stronger lasting longer and writing smoother. Straight edge nibs may not have this beaded tipping (like calligraphy pen nibs) but another art friend showed a music nib with the tipping (that has a straight nib tip).
So between the two pens, I like the Hero best. It's just a nicer pen all the way around. A bit heavy but smooth to work with sketching on paper with few problems. And the angle of the nib is just better for how I hold my pens making it easier to adjust for line widths.
The Sailor is a good pen as well once you get used to how to hold it and taking care the edge of the feed doesn't hit the paper as you use it. It's lighter which is a plus. I'd take it out sketching on location before I would the Hero simply because:
#1 - I wouldn't want to lose my Hero pen
#2 - The Sailor is lighter which makes my gear lighter
#3 - You can carry an extra cartridge right inside the barrel
#4 - If you lose the pen, it's not that expensive to replace
Note: Although you can get a converter for the Sailor in order to load your own ink and save on cartridges, a lot of people complain the ink capacity is not the greatest. Also, the ink that comes in those cartridges are water soluble so not a good choice if you plan to take watercolor to your ink sketches.
Now for the arrival of the Sailor Fude 40 degree nib. Will share another comparison once I've had a chance to try it out :-)