All right I'm new here and this is my first post, so I'm gonna preface it with some backround. I've been in the Mo ( and driving MLs for almost 12 years now) Infantry not trucker. I've been a professional truck driver, for 10 years. Recently, I spent 7 months in Iraq, pulling fuel tankers for KBR from base to base. My opinions are based on these experiences. As far as cab over design being a liability, when Mines or IEDs are concerned, At KBR ( where we ran European cabover Volvo's and Mercedes Actros trucks) we found the opposite to usually be true. Iraq may be an anomaly, but most IEDs were detonated on the right side of the vehicle at ground level. This placed the motor in the ideal position to protect the driver, if it went off under the truck. If it was beside the truck, our Kevlar blankets did an excellent job of stopping fragments and even AK fire. That being said, my vote would still go to the Oshkosh. First, I love the motor. I have driven trucks with virtually every motor available in the 12 liter 425 horsepower class. Series 60 Detroit, E-7 Mack, D-12 Volvo, and the C-12 Cat. I love that motor. Regardless of what the numbers say, the one I had when I pulled turnpike doubles in Alberta would outpull an N-14/460 Cummins. The 3126 Cat, even with it's rating of 330 horsepower, is IMHO up to the task. At only 7.2 liters, it's just too small, especially what you start moving sea containers and the like. Keep in mind that the 300 horse motor in the HLVW is 10 liters in displacement. That's a Chevy v-6. But seriously, the more understressed the motor the better. Especially for military applications, where long life is major requirement. The 3126 in the FMTV is at the upper end of its performance envelope. The C-12 isn't. The 3126 has a checkered past in commercial service anyway, even in the lower ratings. The independent suspension on the Oshkosh is a pretty advanced setup and certainly more complex than the leaf spring and sway bar arrangement that the FMTV employs and that counts against it. Plus coil springs are a pain to change compared to leaf springs, and these are some coils. But it's not an overly complex setup, and I think that the benefits in ride and the lower resultant stress on other vehicle components help to make up for the complexity. If it's simpler (is that a word) but you have to fix it more, is there any benefit.
Also, and I think that this is a major benefit, the Oshkosh, has a more modular armour kit that attaches to the existing Cab Structure. If you want to up armour a FMTV, you have to put an entirely new cab on it. You want to talk logistical night mare.
And going from the user feedback perspective, many Army personnel that I talked to weren't totally in love with the FMTV. It's more comfortable versus the old trucks, but it has some reliability issues, in Army service. I couldn't get them to elaborate on those issues though. The marines I talked to had no complaints and many praises for the Oshkosh. If that's anything to go by.
Just my $0.02