Ok, I've just switched from a day-pack (with internal stays and lots of load securing straps) to panniers. I don't quite know what to make of the panniers yet though.

IN general, the daypack has lower lumbar support, which felt wierd when bent over the handlebars. Other than that I could carry ANYTHING on it, inclulding bikes. I've never tried a mess bag.

The panniers make the rear wheel VERY heavy, since the 25+ lbs that was on my back is now behind the rear axle (needs to be that far back to clear my heels). I can't skid anymore, but my resisiting can slow me down faster. When standing up on the pedals, the front wheel seems more wobbly, and the weight in back seems to want to push me straight ahead. ALSO I find it harder to trackstand, which seems counterintuitive, since all that weight is now so much closer to the ground.

I was wondering if anyone (zealot?) had similar funky feeling rides when just swithcing to panniers, and if this will all seem natural in a week, like picking up fixed riding.