Rolf, everyone has their preferred charcoal. For convenience, I use Stubbs briquettes which is available at most Lowe's Stores for about $8.00 a 15 lb. bag. If you are running low, it's easy to run down and get some. I have never tried Cowboy's charcoal but would love to hear from any that have. I is also available at most/some Lowe's Stores. Kingsford has been around for a long time, but the "rumors" I hear are they use some fillers that are not as good as some of the others. I'd just experiment and see if you can tell any difference. I hope to hear from some others on this, as I'm open to trying a different charcoal.
Thanks for the tip Chris, I was not aware of this fact. I appreciate it, and this forum.