My first progressive was a Dillon RL550b. After using it for a few years. and tiring of its limitations and problems, I decided to try a LoadMaster.
I used the Red and the Blue side-by-side for over a year, and eventually sold one of them. No, it wasn't the Lee!
There are now 2 LoadMasters on my reloading bench, and I'm very happy with them. My only caveat is that they must be set up, adjusted, and operated EXACTLY as the manual says - no exceptions. If you can do that, they'll work wonderfully.
The one time I needed to talk to Lee's Customer Service department (to order a replacement for a part that I broke through stupidity), they were helpful and courteous. Oh, and they sent the part out at no charge and via Priority Mail...!
This is in stark contrast to Dillon's customer mis-service department, who will say outrageous things just to avoid dealing with problems. A couple of my favorites:
When asked why NONE of the *four* Dillon powder measures I owned would meter Universal Clays with any repeatability: "Hodgdon powders are crap - everyone in the industry knows it. You should be using Winchester, that's what everyone else uses."
When I asked if they were ever going to make a bullet feeder for any of their presses: "Dillon makes HANDloading equipment. If it puts the bullet in the case for you, you're no longer HANDloading, you're MACHINE loading. If you didn't want to get into HANDloading, why did you buy a HANDload press?"