Well, as I've mentioned on the forum before, I inherited a 1985 Thunderbird Turbo Coupe with 14,000 miles on it when the car was about 8 years old. It had been my stepfathers car, which he bought new in 1985, then it passed to my mother, the proverbial "Little Old Lady from Pasadena" when my stepfather went blind two weeks after buying the car.
My wife decide she wanted to drive it as her DD on her 100 (round trip) mile daily commute from L.A. to Orange County. During my wife's use of the car it ran well and held up fairly well. She put another 15,000 miles on it.
Driving impressions of the car are as follows. The car was a very good handler for an American car of the eighties; it cornered and stopped very well. This particular car was and automatic which again was a decent for feeway driving. My only real complaint with the car was that in city traffic the the little four cylinder engine just was very slow till the turbo cut in, which city traffic didn't allow to happen very often. The car being a real "sport coupe" was rather tightly suspended and the steering was fairly quick with more feel than you would expect of a Ford. The car just wasn't very quick, unless you had room to wind it out a bit.
My biggest complaint with the car was that the driver's side door panel and arm rest came loose and was never able to be fixed properly so would dislodge itself every time you tried to closed the driver's door.
Eventually my son took over the TB Turbo and drove it to High School his senior year. Not being a car guy he was not very impressed with this "poor man's" sports coupe. But truthfully they were pretty impressive in the mid-eighties, although I would have preferred a V-* version with all the goodies of the Turbo Coupe. For me it would have made a much better overall car.
However, your liking of the refinements and performance of your Eldorado, and the "Luxo cruiser" attributes of the Buick does not bode well for your enjoyment of the Turbo Coupe; a very different kind of car!