I gotta say that I too thought of a puffer jacket the first time I saw the leather link, but it has actually grown on me and I think I'm going to order one. There is something iconic about the leather loop though. When the original Apple Watch made its debut, I thought the combination of it with the leather loop struck the right balance of elegant and unique (as well as a balance between dressy and casual). That original combo had a retro sci-fi quality that I think may be even louder in the leather link.
As far as the loop vs link magnets go: I have never been bothered by the process of putting on a loop band, and I haven't had any issues with it loosening throughout the day. I like the look and ease of adjustment that the loop offers. I have also seen videos of people demonstrating how easy it is to pull the leather link off your wrist by just grabbing the watch. I'm not concerned about theft, but it seems like some activities (including putting on and taking off jackets with snug cuffs) could yank the watch off. Of course the videos all demonstrate someone trying to pull the watch off, so perhaps the risk of accidental disengagement is overblown. Most people describe the link magnets as plenty strong.
I guess you could say I like both, but the leather loop has always been my favorite AW band. I think I will like the look and comfort of the leather link just as much, but it will never have the iconic status of the original leather loop.