you can quilt on a DSM you just have to go thru extra steps to set things up to your advantage.
start with building yourself one of these tables - this will give you a quilting space of 4-6 feet to rest your quilt on depending on the size table you use.
http://www.youtube.com/watch?v=yAS25v3ZTk0
then get a supreme slider and some sullivans silicon spray to spray the plastic table cloth when your quilt isn't sliding as nice as you'd like.
some people have great success with bobbin washers to prevent backlash but i've never noticed a difference.
finally you want a nice pair of well fitting gloves i like machingers best.
one you have everything set up and ready to go start with mug rugs, placements, etc and slowly work your way up to bigger pieces.