Others say...

"Keurig K-Cup Reusable Coffee Filter"
I have been using this product for the past two weeks. It works absolutely perfect. I have no complaints whatsoever. Sure it takes 30 seconds to wash it after each use, but I save money not having to purchase K-Cups. I have had no spills or leaks as some other people have complained about. I highly recommend this product.

"I don't use it"
This works fine and is no problem to use or clean. However, with the choices and ease of K-cups, my wife and I don't use it. We feel that one of the best things about this system is the variety of coffee. This locks us into the use the pound. Other than that, it is an excellent item.

"Simplicity + Economy - Convenience = Decent Product"
I got my K-Cup Brewer for Christmas and then lucked out in finding clearance 18 boxes Green Mountain and Caribou k-cups at Linens n Things and Sears ($2.50-3.75 a box, not the INSANE $9.95 retail pricing). The deal here on Amazon is pretty good two (2 boxes (k-cups 25 count vs 18 retail) for $20-23 depending on sale/maker...

As far as store bought coffee, I like the Eight o' Clock Columbian coffee and it makes a fantastic cup of coffee with this insert. Starbucks ground can be a little too bitter in my experience. Obviously, this is an entirely subjective matter.

The Kuerig system is a great platform, but a little bit more effort is needed to use store-bought coffee for one cup of coffee. I have two coffee delivery platforms (lol)- the Keurig machine and my trusty six cup French press. The latter can be a time/effort saver but unless you have a thermal carafe (or two are drinking the coffee) the pressed coffee cools all too quickly.

The rest of the reviewers are general right about the upsides/downsides of this insert. I like it. Sure, you have to wash it out every time, but that takes 15 seconds. I rinse out the mesh filter in cold water, shake it dry, and load up for the next cup. I use the coffee grounds for compost for my garden, so this thing makes me a lot less guilty about clogging up the landfills with my all too numerous plastic k-cup empties, too.

Bottom line is this, if you want a 'Plan B' when the k-cups run out and have ground coffee in the house (but no other coffee maker), this is the way to go.

"I'm not feeling the love"
I can understand why people like this product and why there is a need for it. I just don't care for how messy it is, pretty much defeats the purpose of the Keurig machine in the first place. OK I know that there aren't any Keurig coffees that have the intensity of Charbucks but I have a better suggestion. Use the Keurig to supply the hot water and put your fresh ground in a press pot. You will get a better cup that way and you didn't have to buy this thing.

"K-Cup Reusable Filter NOT Good!"
In 11 months I am on my third K-Cup reusable filter. The outer shell that holds the filter basket is made from a cheap, brittle plastic that is designed to fail because it is an inappropriate material for this device. When the flanges on the the first once cracked off, I attributed it to my heavy-handedness. I bought a second, and was exceedingly careful. When the edge of the top cracked off despite gentle handling, I called Keurig customer service to complain and let them know that the filter shells were too brittle. They were very nice, but attempted to chide me for not being careful with it! They sent me a free replacement. When the top of THAT filter body cracked after one month I gave up. (It will just take three more filter replacements until the cost of my B-40 has been reached.) I tried Krazy Gluing the top back together and it sort of works. I won't buy another filter until they start using a material that is more suited for this purpose.