These numbers aren't the least bit relevant to car diesels, though the limited rev band problem is, to some extent. The SD diesel has peak torque from 1750 to 2700, max power at 4000 and redline at about 5000 (when power is definitely tailing off), so it can happily rev upwards. The problem is that there is sufficient torque that in normal driving revs are so low that you drop off the bottom of the rev band - 1500-2000 rpm is plenty for cruising but starts to get big turbo lag if you slow at all. Having to dip the clutch to go round city corners, because the engine refuses to be slowed below its idle speed, is common. So having to change down is probably required as much as it was in my previous non-turbo justa Cooper. Having converted to diesel, I will probably convert back next time - the flexibility of the new 3-cylinder engine (peak torque from 1250 rpm!) sounds nice.
True, motors are different, but the biggest issue in the us is fuel.... Diesel fuel quality is shockingly bad here....many places sell so little, they sell untreated no2 in the winter leading to gelling or the leftover no1/2 blend ( no2 has a lower tell or clound point) in the summer leading to lower mpg.... In the north american market, diesel fuel is a heavy truck fuel, and few shops work on diseal motors.... Anybody that has know a person with a VW diesel knows of the trials and tribulations of ownership in north america.....Plugget filters from water, black gunk, caused by fuel eating Bactria that grows in wet fuel, etc..... I have looked closely at buying a vw TDI....several times....but the overall operating expenses in the us is actually HIGHER per mile due to the way fuel is taxed in the us....this is what most folks forget....taxes are HIGHER per gallon on diesel in the us....so pump prices are higher....sure you do get more btu's in a gallon, but have higher mantance costs, and lowervperfornce and in many cases, as you found out, less fun.... The reasons WHY diesel have not been brought to the us in large numbers....folks clamor cause they THINK it is the in the us too.....
Unlike the rest of Europe, Britain bought few diesels until about ten years ago - nowadays we buy more diesel than petrol/gas, so the tipping point can creep up pretty fast. Here, now that diesels are 'normal', the second-hand value of diesels is much higher than petrol/gas, since fuel consumption becomes more important to owners of older/cheaper vehicles. In many cases for larger vehicles (well, larger by European standards...), it would financially be worth buying a diesel just for the increased resale value. All the "you can't recover the diesel premium in less than 10 years" tales ignore this. Some vehicles are now no longer sold in petrol/gas versions, because they are unsellable after a few years - for example, the Voyager (a big minivan by European standards) comes only in diesel.
I understand that in the United States will be so long before diesel engines conquer the market as is the case for years in Europe and especially in Italy.