produce better concentric ammo than say a RoCkChucker or other single ram press?

Theoretically yes, it operates differently than other presses. The jaws and die holder have some play in them. Which in turn allows the brass/cartridge to align better as it’s being used hence the co-ax name.

But in my experience dies are a greater influence than the presses used. Custom dies cut from the cartridge reamer you’re using provides the best uniformity. They match your rifles chamber exactly.

Doing wildcats causes you to make your own dies sometimes. Some smiths will cut the dies for you with the same reamer when they chamber your barrel.  If you own the reamer you can get die blanks cut for you. Or you can send in 3-5 pieces of brass shot in your chamber and they will cut it to your brass specs.

I’d recommend Neil Jones

I just got a Forster and I'm using regular Redding dies. Comparing the Forster to the Lee and other single ram presses the alignment is better throughout the stroke. Very little play in the ram on the Forster.

Some have had issues with the Redding competition seating die height just something to be aware of if you aren’t already. It’s a great press brother 👍🏽