I just picked up a new 3861 Hesalite on the fabric strap. I posted a couple of months ago about my visit to the Omega boutique to see it for the first time and being a little non-plussed with the exception of the new bracelet, which I bought and they put on my 1861. The more I read about the updates, read reviews, and looked at pics the more I was intrigued. The anti-magnetic property and hacking movement in particular were of interest, as well as just a more accurate watch (my 1861 was never particular accurate).
I emailed a watch dealer who's my go-to and always pays me very fair money for watches I'd like to sell, as I absolutely hate having to sell them myself. Just too many scams and nonsense to chase an extra 10-15% IMO. He asked me what I wanted for the 1861 and I gave him a reasonable number that was fine with him. I kept the 3861 bracelet to use on the new watch.
I briefly entertained the sapphire sandwich, but once I saw them both I knew it had to be another Hesalite. I also really liked the technical looking fabric strap on the 3861 Hesalite. So now I've got a 3861 with both a bracelet and a cool new strap, for a relatively small incremental cost.
I can't comment in timekeeping yet, but the very subtle difference in details are more noticeable the longer I wear and look at it. It feels a bit easier to wind and maybe even wears a bit smaller, probably an illusion due to the shorter pushers. The finishing on the dial is finer to my eye as well.
I still agree that if you've got an 1861 that with the exception of the bracelet it might not be worth the cost to buy a 3861, but this made sense for me and I'm pretty happy with it.
