Priming on the co-ax goes pretty fast for me. (An exact priming system, no fuss. )I don't load a ton and have never used a co-ax but do have an old rockchucker. It looks to me like the priming system on the co-ax would be horribly slow. I guess that most guys that use this press use a hand primer too.
I never take my left hand off the handle.
The priming system was a major discion maker for me on buying the co-ax. JM2C