Very low power & harsh 1-2 shift and quick 2-3 shift transmission

[86560SEL]

This is a "spin-off" topic to my other topic "considering 84 300SD". I test drove the car a few days ago and though I have just bought a Lexus- I would like to reconsider it, but have some questions - hopefully someone can answer. On the road, power was OK, but it had a harsh 1-2 gear shift and then it had a very fast 2-3 gear shift. To 4th was OK. Going back up the driveway to the owners house- it was a slightly steep grade. The car was extremely sluggish up the hill. I had the accelerator to the floor and the car was going up the hill at a steady 5 mph for about 10 seconds, then it gained some speed as I climbed the drive. I know this is not a power house, but should this car have more power than this? And what about that transmission- could it just need a tune-up/adjustment? I did not notice any excessive black smoke from the tailpipe either. That "shaking" engine at idle was going away at times- could that still be a sign of bad compression? Any additional advice/information appreciated.