The difference is basically just in the name and the forearm accessories. DD uses barrels with extended feed ramps, and their upper receivers are A4/M4 uppers, meaning that they also have extended M4 feed ramps cut in. This is good for reliability. The VX is just a bare-bones rifle that looks like a basic M4, whereas the M4V2 has better furniture like the Magpul MOE stock and the Omega X rail. Just different looks, really. Same great receiver, BCG and internals, same great CHF barrel.
DinanTronics Stage 1 F30 328i M Sport
Dinan 20" Black Performance Wheels
Gunfighter Training Development and Evaluation
AR15/AR10 Armorer/Advanced Armorer
Gunfighter Training YouTube Channel