I'll throw my 2 cents in on this, as I've had 3 diesel vehicles over the years.
Firstly, a diesel is better suited, especially in lighter applications such as passenger cars, to being used regularly for long distances. Such as frequent road trips, or lengthy commutes. For heavier duty applications like a truck, they excel where you require a lot of power for towing or heavy hauling.
Older diesel engines (pre modern emissions) I would say are relatively straightforward, and for a DIYer, I would say not really all that more expensive to maintain. My reference point for that is a 2003 VW Golf TDI with the ALH diesel engine. Maintenance wise, I really didn't have to do much with it, and sure, it required a diesel rated oil which was a bit more expensive than a gas PCMO, but with this engine, I was good with Rotella T6, really not much more expensive.
My next diesel was a 2014 VW Passat TDI, with the Gen 2 common rail engine (CKRA), which, coupled with a manual transmission, was a real unicorn. Only about 7,000 of these (CKRA engine with the 6 speed manual) were built for Canada and USA (only 2 countries this particular car was sold) for the 2012-2014 years. I only had this vehicle for a short time mileage wise, and maintenance for me was limited to oil changes and air filters. Again, nothing too expensive, but this time, I was limited to a VW spec oil, increasing that cost slightly. Other owners I hear have not been so lucky, with a number of issues being experienced related to the SCR system, as well as a poorly designed Bosch high pressure fuel pump that liked to implode, and turbos that seemed to grenade, along with other issues. This vehicle could have ended up being a financial nightmare, but I actually came out ahead on this one, with my Dieselgate buyback giving me more (only by a couple of hundred dollars) than I paid for the car brand new for nearly 3 years of use.
Then there is my 2013 Duramax truck. Used mostly as my tow rig for my fifth wheel, my maintenance has been so far limited to fluid and filter changes, and new tires. Again, nothing more than would be expected for a gasser, though I am now adding a diesel fuel additive as a preventive measure. These trucks use a version of that Bosch HPFP in the Passat I had, and part of the theory of imploding pumps is that the scar rating of North American diesel fuel, particularly diesel in the USA to a greater degree than Canada, is a major contributing factor. This extra cost (and hassle) in theory will reduce that scar rating, hopefully keeping it low enough to prevent pump failure.
My observations on the driving, you will get phenomenal fuel economy in a passenger car application, particularly if it isn't primarily city driving. You will definitely not have a dragster by any stretch if the imagination, but you will find a useable powerband across all RPMs until just before redline.
For the truck, I don't know if I can truly say there is a fuel economy advantage. That thing is a heavy tank. But it is miles better than any gasser at towing a heavy trailer, especially when you will also have mountainous terrain in your routes. For what I need the truck for, a gasser could not adequately take its place. Similar comments about the powerband, though this feels very much like a lumbering beast if driven gently, though WOT could shame some gas powered vehicles off the line (when unloaded that is).
Either way, the diesel experience for driving is very different in feel from a gasser. Your throttle will not respond as quickly, though there are advantages (fuel economy on the cars, and hauling capability on the truck).
I think you need to test drive a few you are considering to see if this is something you're even interested in.
