I have had the car for over 2.5 years and have had very little issues.
I had some minor issues with the Transmission that cost around $600.
The brakes have worn exceptionally and just replaced the original front rotors because I thought that they must need them at 150,000, back are still original.
3.8 is peppy and gets me up to speed.
I get 29 MPG at 74 and around 34 at 60 for long trips.
I got a 2003 Impala with the 3.8 for my wife because of the non issues.
Shame they are not using the engine any more.
Put on Assurance triple tread and helped allot with the handling.
Lacks in style makes up in durability and comfort.
The 3.8 is still available at Buick optionally on the LaCrosse (at least it was for 2007). I disagree with your comment about the LeSabre's style. I think that the previous LeSabre and Park Avenue were far more attractive than the replacemnet Lucerne. I am not alone in this opinion, I personally know several other Buick owners who are turned off by the Lucerne's looks. I assume Buick's sagging sales are largely due to this, which is sad considering how faithful Buick buyers are.