I disagree , Asking a HF guy that works out of a nice ac room vs a guy that uses ham on the trail is like asking a basketball player about were to get a good foot ball helmet .
Well, I disagree with you in turn, and I'll tell you that your analogy is lame. In most cases, those "HF guys" are radio guys...plain and simple and what they do know is RF. Chances are they know more than the average offroading ham who has simply added the basic license and radio to his "kit" in order to make his outdoor experience more comfortable. This easily comprises the bulk of offroading hams whose experience has been limited to only FM. As a radio guy (er, HF guy) that also spends a great deal of time outdoors, I think it's great that offroaders are making use of Ham radio. The more the merrier. It's been nothing but good for the hobby and the industry that supports it. You can open any CQ or QST magazine and see ads that are clearly targeted for this group.
You have to keep in mind that most HF guys played on FM in their in their earliest experiences, and in most cases they continue to do so as they advance in knowledge, experience and license class to play on the HF bands as well. Most "HF guys" will have a greater knowledge of radio signal propogation of all types. Including the limitations of FM signals in mixed terrain (what we do). After all, who do you think is building and placing the repeaters that we offroading hams are using? Chances are it's a bunch of old "HF guys". Who do you think is writing the software that will predict and plot a repeaters coverage given its elevation and surrounding terrain? Yep, those guys.
To generalize or imply that "HF guys", or HF in general is a shackbound activity is ridiculous. Most "HF guys" also have HF and FM in their vehicles and RF doesn't care whether you're on pavement in the middle of nowhere, or on dirt in the middle of nowhere.... so your presumption is false. In fact, where these "offroad hams" might be inclined to recommend only 2m...the "HF guys" would advise that you have both. I doubt any would dismiss FM as being unnecessary. It's tough for me to reconcile this with being bad advice.
Here's the analogy I use:
In the boating community there are four accepted means of communication. One is VHF (FM), which is used for inland or nearshore waters. It's generally acceptable for boaters that make short trips to and from nearshore islands or close coastal trips from port to port. Most "pleasure boaters" are content with this service. And, in the analogy, this would be the equivalent to our 2m/70cm service. A simple FM unit would be my recommendation for people who stay close to home or repeater services.
Second to that is Marine HF. It's the minimum for boaters or cruisers that venture greater distances. It's been made simple and has been channelised for "non-radio" boating enthusiasts and is limited to 150w PEP. This serves nothing in the analogy because we have no equivalent service available for our pastime.
Third are the Amateur HF bands. They are perfect for the boaters/cruisers that venture greater distances or into remote areas. They are not channelised (most) and in most of the spectrum are allowed 1500w. And, like the offroading community, this is also a fast growing segment of the Ham community. The difference being, that most of these ocean-going sailors usually advance themselves into the General class in order to take advantage of HF's greater distance capability. It also affords them the benefits of WinLink (fax/e-mail) services. For the offroader who ventures greater distances or into remote places, I would recommend a radio with HF capability in addition to FM.
The fourth used is satellite phone. And, for all the same reasons mentioned for Amateur HF, I couldn't recommend them enough.
Ultimately, if you're just going out to do trail runs in the mountains or deserts nearby, you'll be fine with FM. If you're going to travel to more remote places, it's not bad advice to say you should consider HF or a satphone as well.