I'm bringing this thread back to life! I saw a MK48 for sale on Facebook Marketplace in PA somewhere. Also on FB Marketplace in PA is a HEMTT for sale, so I was wondering what's better - the MK48 or the HEMTT?
(Also as of this post the MK48 is asking around $10000 less than the HEMTT.)
Reading through the thread, it seems the HEMTT can be driven faster since it doesn't have the articulated rear unit. MK48 owners here have mentioned in the thread that 40-50 MPH is about as fast as it can be driven before handling safety is a concern. Elsewhere I've read about the HEMTT being able to do 60-70 MPH all day long - I guess that's what the Army means by "Expanded Mobility"
Also I'd think there'd be a little less maintenance with the HEMTT from not having the articulating joint and associated steering hydraulics.
Also, there are a couple YouTube videos I've found interesting involving the FPU and hooking a FPU up to a rear unit: