AAV-SU (Survivability Upgrade) to have better water speed?

via Shepard Media.

New rotary dampers and improved torsion bars in the suspension have increased the ground clearance and offer smoother ride. Replacing the water jets with new axial flow machined jets has demonstrated significantly greater efficiency.
This combined with the recouping of reserve buoyancy to 22%, rebalancing the vehicle trim to be more ‘bow-up’ and a possible redesign of the forward trim-vane/bow-plan hold a strong potential to increase water speed beyond the 7kt (13km/h).
Speculation by industry sources suggest that with some minor design refinements (improved/reconfigure trim vane or re-trimming the vehicle) could increase that further.

Here.

The rest of the article is basically a rehash of the info that we already knew (with the exception of SAIC being able to squeeze out an additional 100 hp when they rebuilt the engine...it's gone from 525 hp to 675 hp).

But the increase in water speed is intriguing.  Its also a bit confusing.

We have over 1000 of these vehicles in inventory.  If this upgrade is going to actually deliver the ballistic protection and improved ground mobility that they're shouting about then the next question becomes...Why do we need the ACV?  Does it offer increased performance that will justify the expense?  Does the Marine Corps need to operate two APCs?  What will that do to the AAV Battalions?  Is the plan to have all AAV-SU platoons with a few ACV platoons thrown in?  Will Companies operate mixed vehicles?  How will maintenance work with two different vehicles in the same role under the same roof?

I've been disappointed with the cancellation of the EFV.  Tried to wrap my head around the idea that the ACV (wheeled) would have better mobility than a tracked vehicle.  Been enthusiastic about the BAE-Iveco SuperAV...but now I'm just plain confused.

The Marine Corps needs to get its armor house in order.  If the AAV-SU delivers as this article talks about then why are we continuing with the ACV?  If it doesn't then why aren't we going all in on the ACV?  Marine Air is in trouble, but Marine Armor is in a state of confusion.

The Amos years (and the idiotic ACV 1.1, 1.2 and 1.3) just keeps on giving.