3.5" loading port vs. a 3" loading port = easier and smoother loading.
NO piston to break, tune or clean = less time on maintenance.
Self-adjusting gas volume = Shooting 2 3/4 dram loads up to MAX 3" Magnum loads with no worries of breaking to gun. More versatility over a stage.
Softer recoil = Faster splits and transitions.
The piston tubes and action are in the receiver and barrel, not on the magazine tube. This is also a benefit from a reliabilty standpoint.
SLPs are about 10K to 12K round guns before you need a total rebuild, and hoping the pin holes and receiver will take oversized pins for another 5K or so. The VM is easily a 30K gun. The VM runs 100% out of the box. The SLP takes those several hundred to 1K rounds to be 100% reliable.
I went with the SLP primarily because of the slug accuracy and the one piece mag tube. The VM has the slug accuracy and I happen to have a prototype one piece tube for the VM.
