50 pounds down so far. Started at a 42" waist, down to a 36 now, probably finish at a 34 the way things are looking.

Benefits - I feel much better. I carry most of my weight around my middle (as most middle-aged guys) and dropping 2 touring bikes of weight has made bending easier, sitting more comfortable, etc. I can wear regular fit jeans. Previously I bought painter's jeans or big skater-kid jeans to mask my weight. Same with shirts. I fit into a plain old large now; no more buying 2x shirts to accomodate my formerly ample midsection. I can do more pull ups because it's not like doing them while wearing a 50 pound weight vest.
Drawbacks - I have to readjust my bikes because I can lean over farther now. Still dialing things in. I have to buy a lot of new clothes, including cycling gear; I've got a bunch of 2x bibs and jerseys that are way too big. (This is a benefit to anyone who can use 2x gear, since I'll be ditching it all on the cheap as I replace it.)