I've been carrying a lot this season which has been great, using a SM 4.5 bag. I love the bag, but it's not particularly great carrying that bag for 18 holes in 95 degree weather. Has anyone switched to the 2.5 from the 4.5? I think the actual weight difference is something closer to 2.5-3 lbs. It just doesn't seem to be that big a difference to justify another bag, but my friend's 2.5 does feel lighter. Maybe you'd notice the 2.5lbs over 6 miles of walking?