Prairie dog: I would agree with you except at 7 dollars its worth it just for the little sanding drums and buffing pads and and the other random little bits. The stones and the little bitty high speed cutting bits are actually decent. The little cut off wheels do suck. Its definitely not a complete set, but I have got my monies worth.
I also totally hear you on the little iron slivers. They are fucking horrible and will be in your skin for days. Its just one of those things though. I have some gloves that help, but don't stop all of it.
If you are going to be doing any real heavy duty porting on cast iron you might as well just get a die grinder for your air compressor. Once again I took my broke ass to harbor freight and got one for like 10-15 dollars. Totally worth it.