The one thing nice about Dillon presses are that a lot of people use them. They really got their big start and popularity with competitive shooters. So the advantage they have is that they are well tested and even critiqued. Solutions for any problem have been found and solved.
One such point many anti blue people like to point out is that the Dillon doesn't produce the best ammunition when it comes to the little things such as reloading rifle ammunition when accuracy counts. Personally I'm a pistol guy at heart and I can say I never noticed any problems. However neither has John Wildden. John just happens to be the National Long Range Rifle Champion. I cann't hold a candle to those guys shooting at 1,000 yards.
You might find it interesting that John does use Dillon presses to reload his ammunition.
CONCENTRICITY
This is what the Anti Dillon people like to bring up when it comes to Dillon presses like they are the only press that may have issues with it.
Concentricity refers to how straight the bullet is on top of the loaded round. A bullet that is straight will enter the rifling in the barrel that way. Bullets that enter the rifling slightly crooked do not shoot with their highest accuracy.
However like I said we are talking about the most popular progressive presses on the market. This makes them the most improved presses on the market because many fine people have worked to improve them with after market products, something that really doesn't exist for the others.
If you are concerned about concentricity you might want to add this after market product to your press then no one can say your Dillon doesn't produce the best rifle ammunition possible with the best concentricity.
Just another plus for the Big Blue.
http://whiddengunworks.net/toolhead.html