Now that you mention it, I forgot that there was a 3120 clone movement with a instant date modification (if I understood it correctly) but I had never heard of someone who actually had their hands on one. Very cool. I would definitely love to get one of those one day, thanks for the clarification.Actually the clone 3120 movement with instant date change exists now. I have already built a few 15400 with it.
This may seem frivolous to anyone else but for me, AP watches always comes with instant date change and I do associate it with one of the necessary traits of high end luxury watch brands. Yes I have not stayed up to watch the date change as far as my memory goes but this is evident when setting the time (when you do it the proper way) and also knowing this gives me some weird form of satisfaction. It is just my preference, I cannot speak for anyone else but whenever I see an AP with a slow change date, it tells me that the date gear is either faulty, or the watch isn't truly an AP.
I also agree with you, while it doesn't matter honestly it is still a more premium feeling and is a gen like feature so it makes sense to want it. I just think that it's an expensive upgrade and should honestly only be bought if you're going balls to the walls. Tell me if I'm wrong but I assume you have to buy the entire modded movement and you can't just have your current movement modded. Small deal to some, big deal to others. Until a date snapping 3120 is widely available from TD watches I won't recommend that or say it to someone who is new.