About a year ago we purchased a front load high efficiency washer and the handyman I had install it cross threaded the cold water intake so it was leaking pretty badly. Thinking it was a cracked plastic fitting, I called a repairman who fixed it for a nominal charge and gave me a lesson on high efficiency washers and detergent use. First, he said that with just two of us we really had no need for the high efficiency washer because they are designed for loads that are probably much bigger than anything only two adults are likely to have. A simple top loader would have suited our needs at a fraction of the cost. He also suggested that we use only about 1/3 of the "recommended" amount of high efficiency detergent because we rarely have any laundry that is heavily soiled...the results have been satisfactory and the detergent lasts three times as long!
I recommend the Cleaning Institute's 16-page pdf booklet you can download HERE for complete information. Other recommended reading:
Difference between HE detergents and regular detergents
Which Washer? Regular or high efficiency? Straight Dope
Consumer Reports Buying Guide
Consumer Reports Pros and Cons
Worth the Expense? How Stuff Works