Prior to getting my Bernina 830, I hand quilted many crib and twin sized quilts. I used SITD for any quilt larger than crib size, including king size (usually 120 x 120) I did send a special one to a longarmer a couple of years ago and it was reasonable and she did an awesome job on it. This past Christmas I machine quilted a king size for my DD. I used my Bernina 830 for that one and you can see the methodology here.
http://www.quiltingboard.com/picture...t-t184776.html
So I think it depends on what you like to do and what you feel comfortable doing. Good luck.