747: most money. Most schedule changes. Leave the country on day 1 and return on day 17. 90% overseas. Hard on your body. OK pay. Bad QOL.
777 (from what I gather): DHL. Laps around the planet to the same places. More stable schedule. Mellow folk.
767: junior flying is domestic Amazon and DHL. Senior flying is international DHL and AMC pax. Week on week off (10 days on or 6 days on). Not so hard on your body. Bad pay. Decent QOL.
737 (from what I gather) Hang out around CVG lots. Fly 20 hours a month.
Some southern person can correct/update me. Hope this helps you select a fleet or class date.