Thanks for your inquiry. This is a good question.
The Amana 610504 was the first do-all traditional type combination blade made. The tooth geometry is made up of 1 flat top(raker) tooth and 4 alternate top bevel teeth in groupings of five. The large gullets at the raker tooth allow for deep cuts with improved chip ejection. It was a great choice for the woodworker that wanted a blade to rip and crosscut. This way they wouldn’t have to change the blade whenever they changed the direction of the cut.
The Amana PR1040 is a new and improved version and an excellent choice for a general purpose blade for both solid wood and man-made materials. It has a massive 0.102” plate thickness with expansion slots and copper plugs that practically eliminate vibration. The 40 teeth are ground with a steep 20 degree bevel angle with an ATB grind for crisp clean cuts both across and with the grain. The 18 degree hook angle yields an effortless feed.
Both blade are very good at what they do. I personally use the PR1040 for my all-purpose blade.