constellation reading isnt all that necessary unless your in maintenance or the HE..... even as a maintenance tech , i never use.....if your trying to troubleshoot transport issues, combiner problems, etc, then it becomes utilized, but as far the field goes, 99% of time you will eith see acceptable constellation pattern, or bits scattered all over the place....which translates to bad mer/ber.....
EDIT- why did it show this post as new for me?!!? wtf!?!? its 3 weeks old!!