I can't say anything about the electronic transmissions, but with the old hydraulic one I got it worked fine up to 192,000 miles when I had it rebuilt. I got 103,000 on the rebuild.
Gas mileage on the highway is good, I get 26 to 27.8 This is going 72 to
80 mph. Occasionally I may hit 29 mpg one one tank.
A friend had a 99 LeSabre & had three fuel pressure regulators put on in three years. Other than that it was fine otherwise except for the hinged arrmrest breaking around the hinge.
As the other posters mentioned, as long as you maintain it run along time. Seeing its 10 years old perhaps have a competent mechanic check it over before buying it.
Good Luck
========= Harryface =========
1991 Pontiac Bonneville LE 3800 V6 ( C ), Black/Slate Grey _~_~_~295,558 miles_~_~_
~_~_~_~_U.S.A._~_~_~_~_~_
~~~The Former Fleet ~~~
89 Cavalier Z 24 convertible
78 Holiday 88 coupe
68 LeSabre convertible
73 Impala sedan