These batteries are good. I bought the package and they are better than the original Pentax batteries. Be aware that digital cameras like the Pentax K-r are power hungry cameras and you need a good supply if you are shooting more than one hour of HD video.
Charges in the Pentax charger, holds the charge, runs the camera. Everything a battery should do. Buy it. Don't pay more.
I also own the AA battery adapter, and while it fits well and works, the 1.2V NIMH batteries I use don't have enough juice to make it really worth owning over this battery, especially considering the cost of both items. Initially I though my lifetime supply of NIMH batteries would make it worthwhile, but the fact is that the camera is never happy when I use it. The power lever is either too low to use right off the bat or runs low very quickly.
I bought this as a secondary battery for my Pentax K-30 DSLR. The title does not list the K-30, but since the K-30 and the K-R share the same battery (Pentax D-LI109) I knew it would fit perfectly, which it does. It charges almost as quickly as the original battery, but has nearly twice the capacity (2000mAh vs 1050mAh). It does last longer than the Pentax battery though I havent shot enough to say how many more frames I get out of it over the original battery just yet.
I had also considered buying the AA battery holder for the K-R (also fits the K-30) and using rechargeable or alkaline batteries as a backup instead, but when I saw the price for this battery on Amazon, I couldn't pass.
This is a tremendous value over the original battery. Pentax lists the D-Li109 for $59.95 on their website, and Amazon had this battery on sale for $9.95 when I purchased it. Despite the low price, this battery does not seem to be lacking in quality in any way. Coupled with free 2-day shipping (Amazon Student) I could not be happier.