The kisslock is the #1 reason why I haven't added anymore of this size. I switched back into my regular size one on Thursday to decide if I wanted to add more during this sale. First thing that I remembered was that darn kisslock is there instead of a slip pocket. I also find the zip pocket harder to open on the regular. It doesn't stick, but the cloth lining moves too much so I have to hold both sides to unzip. It does fit all my essentials better than the 25 and 2 water bottles easily.
I thought NO WAY would a 25 work for me, but I'd been using the past 2 weeks and really like it. I tuck the handles in and am able to fit wallet, cosmetic case, card case, keys, gum, chapstick, crackers, mirror and 1 water bottle in there. Phone in slip pocket. For me I like the size better because I can also use crossbody w/a novelty strap. The regular size is too big on me crossbody. I will mention that I don't zip the main compartment of either size because I really prefer open easy access bags.