In May 2010, my family and I had an 6 p.m. flight arrival into MCO and felt that that would be enough time for DME to get our bags to our room before "bedtime." Well, the airline "misplaced" our bags and DME had trouble finding our tagged luggage. Needless to say, we had to buy some nighttime necessities (i.e. tootbrushes, toothpaste, hairbrush) just in case our bags were to arrive after our DD's bedtime (we held them off until 10 p.m.). Our bags were eventually found and delivered to our room by 12 a.m.. (Thank goodness I kept my luggage receipts which were needed by the DME agent!)
So, what I guess I am getting at, I would recommend getting your own bags and taking them on DME bus yourself at that hour. Otherwise, you could be waiting until 12 a.m. or a bit longer for your bags.