Excellent post..I an going to add my 2 cents.
I am also a LAer and my biggest chant 'The LA can quilt it out'...No we can't quilt out hills,valleys,C and D cups,wavy borders or borders that are 4 inches too big'.
The backing is too small....I advised my custs that the backing has to be 6 inches bigger than the top so I can pin it on the rollers and have room to center the quilt.
Inferior batting...I refused to use cheap batting,it tears,stretches,has lumps and bumps that will not quilt out. I carry good bat and sell it to my cust for a reasonable price.
Talk to us on how you want your quilt done..If you tell the LAer to do what she wants...don't get upset. YOU gave her permission to do what she wanted. If you do not tell us,you can't go on quilting forums and say the LAer ruined your quilt. it is YOUR job to tell us what you want..so really think about it before you blame the LAer.
Please do not expect custom quilting with a zillion thread changes and want it for edge to edge prices. It take alot of time to customize a quilt,plan out the pattern and bury threads. I do alot of custom and it takes weeks or longer to a quilt show quality job.