Mike, this is a semi-dumb question,,,,,, but what is the height of your letters? Are they .1" high, or .8" high?
I haven't engraved aluminum, but when I have engraved other materials, the smaller the letters, the worse my results, which is fairly intuitive. And are Gary's letters 2" high? It would seem that without knowing how tall your characters are, and how tall his are, it would make it hard to evaluate and/or compare results.
But I am interested in seeing how much improvement you can get by following forum suggestions, so thanks for bringing this up. Chuck