John,
I decided to pull the trigger on the 5HP splitter from Sportsman's Guide that I linked to in the post above. Living in Texas, we don't heat with wood, so I'm hoping it gives us years of service. The DR splitters (rated at 4&6HP) are supposed to split a cord of wood in two hours, and that's plenty fast for us.
I'll report back on my experience with it, but it will likely be after Thanksgiving. I'm having it delivered to my f-i-l down in Central Texas to test it out.