I should add, that I also made the switch to panniers because I commute to the university and often have to carry 10-15 lbs of books with me, in addition to cloths, shoes, lock, and tools... so the weight thing was an issue...

as for removing panniers I bought a 'cheap' set of bags, which attached by 4 belt type straps and 2 small bungie cords attached to the bag... it would take 2-3 minutes to remove at the most.... perhaps some people are trying to remove the whole pannier rack? which would be a pain considering you have to get tools out to remove it...