I waited a full year before writing this review, even though I was thoroughly impressed with Woolzies XL the very first week. These babies really do work! Will they improve your dryer's performance? ... YES. Will they totally eliminate *all* static in your laundry? ... NO, but dryer sheets won't either, and the sheets don't help the clothes get dry faster.I dry approximately 10 loads a week. After a year of use, the Woolzies have a few pills and one even has a small chunk missing thanks to my dog who chases and retrieves balls much more efficiently than I. The Woolzies utilize escape tactics when you're removing laundry from the dryer, but they are well worth chasing across the floor between loads. Your skills of keeping them contained will improve once you learn their tactics. Although not a pretty as they once were, the Woolzies are still fully functional and look as though they will go another year. (see the photo I've uploaded of a new Woolzie next to my originals that are 18 months old). One reviewer mentioned that they will get in the corners of sheets, etc., which is true, but it does not stop them from tumbling around -- they just take the sheet with them. They will fall in and out of sheet corners many times during a cycle.Even though my dryer has the sensor that is supposed to end the drying cycle only after the contents are actually dry, it never seemed to work out that way. Unless I was drying microfleece or very thin knits, my clothes and other laundry was never completely dry when the dryer stopped. If I were drying jeans or towels, it was not unusual to run the dryer 2 or 3 times before achieving total dryness. It NEVER happens anymore. No matter how heavy or thick the load, the laundry is dry when the buzzer goes off. The clothes are beautifully wrinkle free as well. Polyester knits still have static issues if the weather is really dry (which rarely happens in Louisiana), but a can of Static Guard Static Cling Spray, Fresh Scent, 5.5 oz. kept nearby takes care of the occasional clinging issue.Overall, I know without a doubt that I have saved enough to pay for these several times over, when you figure electricity and the elimination of dryer sheets from my shopping list. These are much better than the competing brands, especially the little plastic ones with bumps, which crack fairly quickly and make a lot of noise bouncing around. These only produce little muffled thunks, instead of steady thuds (you get used to it pretty quickly and the sound disappears into white noise). I recommend these wholeheartedly and they also make a wonderful gift.***UPDATE***: Eighteen months into my use of Woolzies, I got a new HUGE dryer, so I purchased another set of Woolzies to throw in with the old ones. I uploaded a photo which shows exactly what an old, heavily used Woolzie ball looks like next to a brand new one that has never been used. The box that contained my new Woolzies actually reads that the pilling on the Woolzies help them work even better. I'm not removing the pills!FINAL UPDATE: After four years and thousands of loads, I am starting to retire the original Woolzies. With the large capacity of the dryer, I use 18. The original balls are very loosely bound, and many started to unravel. My cat really enjoys batting them around, and doing the final unraveling. I then cut them into pieces and use them as part of the stuffing for pet beds. Nothing goes to waste.