As far as I know, the only stacked dado sets that won't work on the 3650 are the Freud SD600 Series sets. No experience here with the DeWalt set so I can't comment on its quality of cut. There are big differences in the quality of stacked dado sets available along with big differences in prices. I may very well be way off base here but B&D, the parent of DeWalt, also own Oldham so there is a chance that the DeWalt Dado Set is made by Oldham.
111,111,111 = 12,345,678,987, 654,321