We have the Duets, they work well and our clothes seem to last longer. Only problems with them in seven years are the dryer had a small tear in the belt when new, which was repaired under warranty, and the fill valve on the washer died the last day of the warranty. I replaced the fill valve myself, it took about 20 minutes, and the $15 part was provided free under warranty.
The only issue with them is that you need to leave the washer door open, or it will develop mold, this is common to all front load washers as I understand.