The main difference between the Load Master and the Pro-1000 is that the Load Master is designed to handle rifle and pistol, and the Pro 1000 is designed primarily for pistol cartridges, but will reload rifle cartridges up to 2 5/16" in overall length.
The Load Master is a five station press, the Pro 1000 is three. Both include automatic indexing, automatic primer feed and case feed, and both can be fitted with an automatic bullet feed. Both come set up with everything you need to start loading the caliber chosen. People who wish to load rifle or use the Lee Carbide Factory Crimp dies for handgun loading opt for the Load Master.
Caliber changer overs for both presses can be done in less than five minutes. The Load Master is a little more costly to purchase and to change calibers. Both presses are designed for experienced reloaders. That is not to say that a first time reloader shouldn't order one, but one should have good mechanical aptitude to start with a progressive.