I like having the option for the horseshoe zipper on some packs but not others. Personally, I have my larger Terminus pack for all long duration trips when I’m trying to cut every ounce I can. But when I’m not as concerned about shaving ounces, or would like to haul full quarters, I’ll be picking up the K4 with the horseshoe. I really enjoy the ease of access to the pack it provides.