The Black Diamond Lost Arrow is the go-to piton for small cracks. There just aren't many options besides this Black Diamond. I have come across a few other variations but they generally are not as bomber. What makes this piton great is how burly it is. You can beat on one for years and it just keep going. Eventually you will wear down the eye, but it will take a long time. They are generally easier to clean than angles and most other pitons.
Because there is no expansion property (like an angle), these need to be wailed on pretty hard. However, some people wail on them too hard so it's a delicate balance. If you hit them too hard they are quite damaging to the rock to clean. These are also heavy when compared to angles, Peckers and Tomahawks. They do not work nearly as well in sandstone as most other pitons.
Black Diamond Lost Arrows are not as essential as they once were now that there are Moses Tomahawks, big versions of the Black Diamond Pecker that can fit in #1 and #2 vertical Lost Arrow placements. More importantly, the Moses Cam Hook and DMM Brass Offsets often offer a clean climbing alternative to the Lost Arrow. That said, a few Lost Arrows are still a staple on a big wall nailing rack.
Only the first three sizes of these pitons are essential to have. Sizes #4-6 are more for specialty aid racks and, to be honest, there are not many routes where they are mandatory. The #8 (Long Dong) is great for cleaning nuts.
Man, these things are expensive!