As most have said, it is personal preference. I think my decision would rest on several factors.
1) Rarity. Is yours one of only a few produced? A brand no longer manufactured? One of few survivors? The newer and more common it is, the more likely I'd be to hot rod it.
2) Completeness. How much of the original is there? If the original equipment is missing or torn up, you'll have to rebuild or replace. I suspect it costs more to go back original than rod. And if you have to replace a lot, to me it detracts from the "historical" aspect, and the need to go "original". More complete = restore, less = rod.
3)Use. Daily driver = rod. Show or occassional = restore.
4)Money. Perhaps my perception is wrong, if so, please correct me. I think it takes more money to restore. To do it right costs a bit of cash, and your utility is limited. A first class restoration is probably only going to shows or parades.
Most of us can't afford that. We have to use our projects, which means we need safety, reliabilty, and a few creature comforts for our daily drivers.
From my own experience...my dad has a "barn find" 1942 Studebaker Commander with about 20,000 miles he bought 2 years ago. The rat-eaten upholstery had to be replaced, but the glass/drivetrain/radio and exterior paint were still good. You can bet we will not ever hot rod that one. We won't even "restore", since we feel it is more valuble original.
On the other hand, we bought my daughter a '53 AD pickup. The bed floor is gone, seat ripped to pieces, the engine is bad. It will be more of a rod than a restoration, due to safety and reliability.
I like the suggestions of the combinations. For instance, my daughter's pickup may get a modern engine and brakes, but we will do our best to not destroy the overall integrity. No chopping, hood louvers, etc.
Again, to each his own, but I want to leave it where someone can restore it in coming years if they wish.
One more point (I know, too much information). I like the way 235 fat fenders did things. My dad also collects antique tractors. Some of them were extensively modified by the farmers during their working days. So the question is to restore them to "factory" or to "period". For instance, Dad has a wheatland A John Deere. The original owner cut out the gas tank and installed a butane tank (nicely done, BTW). Dad choose to keep the butane tank rather than go factory.
Just one more way to preserve history.
