I think I might be some help. Below are the similarities and differences between the racks.
Delta-13 Elite:
1. Made in the U.S.A.
2. 6061 Aluminum
3. Anodized in the colors listed on webpage (www.delta-13.com)
4. Ergonomic Grip
5. CMM report (measures the rack to make sure it is within tolerances and is a "perfect rack" or "A true triangle" measurement)
6. Identifies undersized balls
7. Reduces cloth wear
8. Comes with engraving on two sides
9. Center alignment marks
10. Lifetime warranty
11. 3 rails and 3 corner design
Delta-13 Select:
1. Made in the U.S.A.
2. 6061 Aluminum
3. Anodized in black and silver grey that are listed on webpage (www.delta-13.com)
4. Ergonomic Grip
5. Does not include CMM report, but racks are measuring up to the Elite when we are checking every so many
6. Reduces cloth wear
7. Engraving is extra on two sides
8. Center alignment marks
9. Lifetime warranty
10. 3 railed design
Delta-13 Regular:
1. Made of Cast Aluminum
2. Powder Coated
3. Comes in various colors
4. Does not offer engraving
5. Does not offer CMM report
6. One piece cast
I hope this helps! Let me know if you have any more questions and I would be happy to answer them!
Delta-13 Team