Why does one need to tow to own a diesel? Does a V8 Mustang owner need track it order to own one over a V6 to justify the added $6k? Does a 4x4 truck owner need to take it off road to justify the added $4k? Does a Laramie truck owner need to use all of it's features to justify the $11k over a Tradesman?
I never understood the logic of someone throwing down $11k on a Laramie option without batting an eye, but question whether they "need" a diesel or not. For me, it would be reverse if I wasn't blessed to have money for both. I would easily throw the money down on an $8k diesel option over an $11k Laramie option. Although, unlike the Laramie and many other options, the diesel option is the only one that actually pays for itself with added towing performance, better fuel economy, and resale. Last I checked, a Laramie option doesn't do anything for fuel economy or towing performance.
As far as using Fuelly, it is the only real world numbers available. Most on here like to quote computer numbers and from my experience the computer is 1-3 mpg optimistic many times. There have also been many people here who have stated that 12 mpg is an accurate average hand calculated number and 13-14 is what the computer shows when their hand calculated shows 12 mpg.
In short I answered applicable to what was asked. You answered as applicable to your personal preference with no answer to the question, because to your personal preference there isn't one. So it likely helped them zero since they were already considering a diesel. Even the mileage comparison wasn't addressing the mentioned highway specifics, instead using a program's over time response.
And then you decided to attack me by bringing up the Laramie topic simply because I have a Laramie (best I can tell since there was no other prompt). Well, that and the 4x4 combined with it. As you stated yourself the option doesn't do anything for economy or performance so why would you be bringing it up aside from trying to belittle me for no reason? And I sure didn't pay $11k for a Laramie package anymore than I paid $64k for the full truck, just like the OP won't necessarily pay an $8k difference in diesel over gas, especially on a used one. There are other considerations as well due to family but apparently you're either too short-sighted to think someone might have reasons, or just feel like being an ass on the computer because you can. Maybe both.
The question was about longevity, mileage, and purpose. If the question had been about comfort or options I would be happy to argue against a Laramie instead of an SLT if the OP had said they don't want leather or other things, same as I've made the arguments for diesels over gassers. Or possibly for it if they said they wanted those highway miles to be more comfortable in all temps and didn't like their hands freezing on the steering wheel, or needed the additional options if kids would be in the back. Just because you're short-sighted or don't think something is worth considering doesn't mean no one else would have a necessary use for any of it.
The question was also specifically as to any reason why the Hemi over the diesel. Not why the diesel over the Hemi. OP is already looking at a diesel, and sounds like probably going to get one. So good on 'em. But they asked about possible benefits in comparison. You being an obvious diesel-pusher selling the diesel doesn't answer the question.
I'm not going to argue the benefit of something if it has no considerable benefit over another when that's not the question. Since the OP is not towing, let alone towing heavy things up a hill, it takes almost all of that considerable benefit out. It's been shown the maintenance/mileage/DEF/cost/etc. arguments essentially zero each other out, or are at least negligible either way. So I answered the question with my experience relating to what was asked. And I've claimed nothing more, and I haven't said they can't buy a diesel if they want even if not towing anything. Anything left after that is opinion, and lands squarely in the realm of "buy what you want" - in which case almost any input we give is irrelevant. Hence why I listed those questions as what would 'matter' in a comparison, because if it's just because you want one as you're going on & on about none of that would matter in the end.
I've already pointed out the computer on mine quotes 1MPG over actual, and it's rather common knowledge. So you're going to use a computer number to refute another computer number, because the computer's inaccurate, even though your computer is inaccurate regarding the question. If I used that Fuelly thing it'd probably say mine is 11.5-12. And I've stated to that effect for my daily driving. But it wouldn't be an accurate representation of highway mileage anymore than the truck's is (actually worse). Yes I've seen some listing the 12-14 numbers so far. I've also seen a few have said 19-22, although very few. But reading through this thread and several of the others so far lands it more in the 16-18 highway range on average from personal experience. However those you discard and only mentioned the 12 because it fits your purpose. Everyone else saying that is wrong and you're right. Suuurrrrre.
If your feelings get hurt that easy over someone answering the OP's question you might want to go back to the school yard. There was no need to try and make it a personal attack. I was even agreeing with your post in the quote. I'll try to remember not to make that mistake again.