I guess it would depend where the quilt lies on the bed... if it needs to be a bit bigger to hang over enough then I think a border is necessary. However, your quilt top is beautiful just the way it is so... if it is already plenty long/wide enough to hang over, you may not want to add a border.
Funny I posted that comment because I always put a border on my quilts.... but I love the look of yours with or without a border!