This is my first stab at trying to quantify the comparison of two stored procedures.
For a more complete explanation, please go to my blog entry here. In this example, set the database to one of your own, and change 'spd1' and 'spd2' to the names of stored procedures you are interested in comparing.
Here's a sample of that blog entry that summarizes what this script does:
"I started my analysis by reading each spd into a table, line by line, so that each row in the table represented a line of code from the spd, and then compared the number of lines from each spd that matched lines in the other spd."
Written by Jesse McLain