I've tried lots of pens over the years. The ones I can remember:

• Conid Bulkfiller Regular
• Cross Aventura
• Jinhao 159, X450, (also whatever the Safari clone is, 777 I think?)
• Lamy 2000, 2000 Amber, Safari
• Montblanc 145, 146, 149, 320, 1912, Slimline
• Nakaya Decapod, Neo-Standard
• Parker IM
• Pelikan M200, M600, M800
• Platinum 3776, Preppy
• TWSBI 580, Eco, Vac 700
• Visconti Homo Sapiens Bronze Age, Dark Age
• Waterman Phileas Blue

I'm not much of a collector, so I have cycled through and gotten rid of almost all of these. I only have around ~10 now, just the ones that I really like, or are sentimental, or are just super unique. One brand that's escaped me is Sailor. I've read about the 21K nibs and how people fawn over them. I know there are die-hard Sailor supporters and it seems to mostly revolve around this nib. But, $300+ for a proprietary cartridge/converter that isn't made from unique materials seems like a lot.

So, if I was going to "try" Sailor, as a manufacturer, where does it make sense to start to see if I get it or not? Do people prefer the Realo (piston filled) variants? From what I can tell here and on /r/fountainpens people are mostly content with the C/C versions. So is it just the unique colors? Or is it just the 21K nib and nothing else matters?