I also have the Brothers 1500., My Dh made me a quilting table by cutting the legs off an old kitchen table and adding 2 layers of foam insulation. Here is the link to the utube how to make the top.
http://www.youtube.com/watch?v=g14govA4pIM
He put on the foam top and then adjusted the table height so it is ergonomically correct for me. This really gives you a lot of quilting space and can also be (sort of easily) removed. Actually I keep my machine in it all the time even for piecing. Lot of room to spread out. As for accessing the bobbin- yes it is a pain. I have to lift my machine up to get to the bobbin case. Oh well- I still love this machine. Also this set up can be used got other machine as well. I put my brothers on a board to raise it to even level but my Singer fits in it without the board.