What can I say? It's a Caprice! I've had mine for 3 years now and put 45k mils on her. It's been very reliable so far minus a few little electrical issues. This car has never broken down on me and left me stranded. The L99 (4.3L)which is identical to the LT1 (5.7L) but with smaller stroke and bore is very adequate for city driving especially with some power programming. Gas mileage is very good for a 2 ton vehicle.
Looks great, cheap replacement parts, very comforatable. Takes well to a wide array of mods.
Improvements? That's a moot point considering they don't make these babies anymore. It's got the typical mid grade GM plastic. Some other folks have issues with the optispark distrubutor common to all other LT1 powered cars.