We do the same. There is no reason to go to exit 3 and really is the wrong way to do it. Exit 6 takes you straight into Disney near Epcot and every resort can easily be reached from it, even All Stars. Just check maps before you go and follow the signage which is very good.
We have tried both the north exit from MCO via the 528 and I4, and the south exit via 417. We now always take the 417, anything to avoid I4 and extra price very much worth it for quieter drive and lighter traffic.