As I wrote the other day, each fountain pen I have was bought for different reasons or for different attributes (beginner, demonstrator, flex nib, long cartridge etc). On top of that, each pen performs differently. What follows are my observations and comments on some of these attributes and performance. Some of these thoughts are personal and subjective whereas others are statements of fact about each pen.
1. Lamy Safari
+ Relatively cheap + Beginner indentations to assist pen holding + Replacement nibs easy to install, and relatively easy to buy + Smooth and comfortable to use - Somewhat cheap feeling/looking - Proprietary cartridges ^
2. Pilot Metropolitan
+ Somewhat classic look/feel + Relatively cheap + Snap cap feel/sounds solid - Proprietary cartridges ^ - Suffers from nib creep ^^
3. Kaweco Classic Clear Sport
+ Demonstrator (in the clear) + Small and light + Can be used as an eye-dropper for dramatically increased ink capacity + Accepts short standard international cartridges - Plastic body scratches/marks fairly easily - Needs caps to be posted to be useable for medium to large hands
4. TWSBI Diamond 580AL
+ Larger pen + Interesting filling mechanism (twist piston) + Smooth nib (M) and clean writer + Relatively cheap replacement/additional nibs - Easy to strip the plastic threads when disassembling/assembling - Threads are reverse-threaded
5. Kaweco Brass Sport
+ Smooth writer (M) + Some heft or weight to the pen + Accepts short standard international cartridges - Needs the cap posted to be comfortable to use
6. Noodlers Ahab Flex
+ Cheapish + Flex nib + Can be used as an eye dropper - Ink accumulates on the bottom of the feed - Suffers from nib creep ^^
7. Pilot Falcon
+ Flex nib + 14ct gold nib + Can be used as an eye dropper (if the finial seals properly) - Proprietary cartridges ^ - Suffers from nib creep ^^
8. Retro 51 Tornado Lincoln
+ Antique copper look + Accommodates long (and short) standard cartridges + Uses a #6 size nib - Suffers from nib creep ^^
9. Lamy Studio
+ Stylish looking pen with propeller-shaped clip + Smooth writer (LH oblique nib) - Proprietary cartridges ^
So that’s the wrap up of my current pen stable. My most preferred pens to write with are the TWSBI 580AL, Kaweco Brass Sport and Lamy Studio.
^ Proprietary cartridges are not an issue for me as I tend to mix inks and use a blunt syringe to refill cartridges and converters.
^^ Ink creep is misleadingly named. Refers to ink accumulating on top of the nib having crept up between the tines. Perhaps better named as ink-nib-creep.