I think it is an issue of buying new or used. Buy a new gas or an older diesel are your best money choices. Anything else is something else.
The gas suspensions at around 35 feet seem to be just as good as the diesel, based on my test drives and conversations with gas owners. When you hit 40 ft, you must go diesel. You can get a Newmar Canyon Star gas diesel equivalent, for the most part.
One gas owner I know feels that the best advantage of a dp is minimal rocking when you go through a corner. You won't hear that point of view very often.
A dp wins hands down as to noise and braking, and full time usage. A v10 can outrun many dps and is great for vacationers and toys and such...and some use them for full time as well.
Really, though, if you want to spend an extra $100k on a dp and can, well that is that, but don't try to cost justify it as it just isn't.
You can also buy a hd semi truck and pull what you want.
No, I don't think this is secret knowledge and of course it is personal.
RVing is at its best, as I see it, as an entertainment/vacation dream realized and as such is not a financial investment, but an entertainment cost. For some the dream can become a nightmare at times.
I have no clue what the full timers think as it is beyond my imagination wanting to live full time in something that was designed as a temporary mobile lodging. However, there are some people who are forced to live in something other than a brick/stick house...that is another issue.
Frankly, I also like spending time overseas and usually that takes a boat or plane to get me there, so $100,000 extra will pay for a lot of that...
Because I have taken the time to get my rv service technician training and rv inspection training, it is a good bet that I will end up with a used 99% perfect used diesel pusher as it simply would not be fun to buy new. However, what I think of as perfect is not what "some" will ever understand.