whats the deal with these diesel engines

[shrtbx]

I havent really payed attention to diesel engines much. I always heard they were slow and always had lots of problems. But yesterday i saw, for the second time a diesel engined vehicle dust a hi performance car. It was actually an old impala dusting of all things a lamborgini. Now am i missing something here? Tons of power and torque along with great gas mileage. I did notice parts are sky high on the motors, would that be a discouraging reason why people arent using them? So far looking through some posts on here its kind of 50/50. Either people love them or hate them. What do some of you think. Would it be worth it to stick in a new style diesel engine in my 86?