jm51 wrote:I still would like for someone to be able to tell me how these products are better than my straight edge on a board?
I'll try to answer this question.
The best one is the one that fits your needs!
In my opinion, a straight edge is a straight edge, as long as it is straight!
If a straight edge is used as a guide for sawing/routing/scoring/etc. it is a often called a saw guide.
If the saw guide has a feature that holds the saw/router/ or other tool from wandering away from the guide = it is called a tracksaw (I think

)
If a woodworker uses either a straight edge or a saw guide or a track saw to
mill straight lines successfully then there is none of these any better than the others. In my opinion! The best one is the one that better fits the needs of the user.
Some folks prefer to use a multi dollar tool to do what can be done with hand tools. This choice is clearly up to them.
If a contractor thinks he can save $ by using an expensive tool and thereby save customers $. He should choose the more expensive tool. If a hobby wood worker likes the expensive tool (or brand of tool), he/she should use it, if affordable.
Final thought as it applies to my shop - a straight edge is a straight edge. I have one especially made for drywall installation. You've seen my saw guide in a previous post.
Octogenarian's have an earned right to be a curmudgeon.
Chuck in Lancaster, CA