I also habitually carry fountain pens, a ball point or gel pen, and a mechanical pencil (Pentel Graphgear 1000). My EDC fountain pens typically includes a Visconti Homo Sapiens Maxi Bronze Age, Pelikan Souverän M805 Ocean Swirl, and a Lamy 2000 (inked with Montblanc Oyster Grey) in a leather pen case. I also carry a Kaweco Liliput with a Monteverde green refill when I'm traveling and it is impractical to carry/use my pen case.

The vast majority of my writing, however, is in fountain pen. It may not be as convinient as a ball point or gell pen, but the writing experience is just far better--especially for more expensive fountain pens.