Are there special parades or fireworks in the MK that night you arrive? If so that will make the MK quite crowded. I think were you go depends on a lot of things...like if you've arriving after a long car trip, whether you have kids and their ages or the ages in your group - and what special events are on for that night at the MK and elsewhere. If it is a long drive down and with young kids I'd eat some lunch at the hotel and go for a swim and rest and then hit Epcot for the evening - and take in dinner (get a PS) and watch Illuminations. It is hard to stay away from the MK though! If you need a relaxing evening you could do the same but make the PS at the MK and just enjoy the atmosphere there and maybe pick up a FP for a popular ride. Have fun!