Update queries slower after enabling SQL Server Full-Text Index
In my case I had to change an inefficient UPDATE statement: 

Before:

UPDATE Customer 
SET Rating = 'Not Rated'
WHERE ...


After: 

UPDATE Customer
SET Rating = 'Not Rated'
WHERE ...
AND Rating &lt;&gt; 'Not Rated' -- THIS LINE WAS INSERTED


This improved performance from 4 minutes down to 5 seconds. The problem was that I used to update all rows, even if they already had the value that I wanted to assign.