Product review (3 stars): Don't last nearly as long as advertised.
They are okay. Water tastes fresh and clean, which is great. Unfortunately, they don't last nearly as long as it says they would (6 months or 200 gallons). For us, with fairly soft water and not much to filter out at all, they last about 3 months until the water flow becomes so low that it's time to replace them again.

So you can buy these, but keep in mind that they will probably only last half as long as the originals, making them not so cheap after all.