Update on my ZF54 for anyone curious on longevity of hard usage:
I wear this watch almost daily as my work watch (Project Coordinator in a Geotech lab). I'm coming up about one year of wear. It's almost constantly exposed to water, dust, and abrasive materials. I've also worn this watch in long showers countless times. I've submerged it for minutes it at a time in sinks and tubs without any clouding of the crystal or signs of water entry. I HAVE NOT gone swimming with this or submerged it in any hot bodies of water (ex hot tubs, baths).
I have definitely banged this watch against anything from concrete, rock cores, steel counter etc. I do have a very small and faint scratch on the sapphire crystal - I believe this was from a steel counter top corner. The aluminum bezel is NOT resistant to Sodium Chloride (Lye) (Who would've thought!) This bezel does get stiff if I'm exposing it to large amounts of dust - but once I run it under some water for a few seconds while turning the bezel , its good to go.
The bracelet and finishing have been surprisingly resilient, with no significant scratches or deep cuts in any part of the watch, aside from the normal desk dives on the clasp.
Upon arrival I noticed the watch runs about +15 seconds a day and still continues to do so - cant really complain there. I did notice a bit of a looser feel after a while when pulling the crown out, Not sure if the setting lever is wearing out or the crown stem has become worn. Or perhaps it has just loosened to the appropriate tension and was actually stiff before hand. Regardless, its not as clicky so that makes me feel as if a part or parts are worn.
I would like to Sellita swap when the movement becomes damaged beyond use, but it keeps decent time still, so we wait.
I have not opened the caseback, as I assume that will breach whatever luck of a water resistance I have on this. I'll save that for the movement swap and hopefully I'll be able to get it pressure tested enough to know my limits with this.
I don't regret this purchase at all. The watch does what it needs to do. I can still use the bezel to keep track of lab tests & the lume shade difference doesn't diminish from its utility in any form.
anyways TLDR - great watch, love the bracelet, still durable for a rep, I'll update if anything tanks in the next 6 months.