This is my 2 cents....
There is no perfect saw. Some excel at one or two things but fall short on other things. Then there are those saws that excel at nothing. Some are easier to tension. Some are easier to change blades. Some are easier to do fret work then others. Some will cut a perfect 90 and others never will. Some are top feed only. Some are bottom feed only. Some can do both. I own or have owned 5 different brands (Dremel, Dewalt, Hawk, Excalibur and Hegner). The Hawk and Hegner I got second hand. The two that I am running right now are the Excalibur and the Hegner. I also cut some puzzle but more like 50 - 60 per year. For your puzzle making I think the Hegner will outlast 15-20 Dewalts before doing any maintenance . Now the down side. Because Hegner is cutting a true 90 (front to back blade movement) it will cut slower then the Dewalt. It also requires a tool to change the blade. If I was in your shoes I would bite the bullet and get a Hegner.