EFV lite is the ACV future.

Check this out from AOL's Breaking Defense.

“We’ve done the homework now. It’s taken three years of a lot of rigorous analysis to figure out the high water speed business,” Amos said at the RAND event. (RAND is closely linked to the Army and the Air Force, and Amos is the first Marine Commandant to visit that he or anyone else I talked to can remember). “You can build a high-water-speed vehicle and you can make it affordable — yes, I’m convinced of it — but the issue is the trade-offs in the capabilities inside that vehicle.”
Within the limits of current technology and budgets, it seems, making an affordable troop transport that can skim across the water at high speeds requires too many compromises to its capabilities as a combat vehicle once on land. And while Marines come from the sea,they fight on the land.
“This vehicle will live predominantly, probably 99 percent of its time, ashore,” Amos said. “In Iraq we had our amphibious tractors ashore; we had hundreds of them ashore,” for years.

Read the entire article, but a quick decode....a transformer type ACV is going to cost too much, and although we were real close to making it work last time, we're broke because the F-35 is raping us.

Which leads me to my next bone of contention.

Why did we do this entire exercise?  Why didn't we ....
1.  Jump all over General Dynamics offering of a non-planning EFV that they practically begged us to take (at what is rumored to be bargain basement pricing) or...
2.  Wait on tech to develop and purchase the BAE Super AV now (which I'm being told by little birdies aced the swim and blasts test..AND we could get for a song).

Instead we're still looking at getting a new vehicle in 2020-2025.  The sad thing?  No one in the region is waiting on the USMC to make a decision.  Everyone is developing a Marine Corps and everyone is acquiring vehicles that are more powerful than the long serving AAV.

The Marine Corps has aviation well covered.  Even when the F-35 fails, we'll still have AV-8B Harriers (thank you Brits) that will be viable until 2030.

The current vulnerability lies in troop lift to the edge of the battle.  The AAV and MTVR are poor substitutes for a dedicated and capable armored personnel carrier/infantry fighting vehicle.