The Tristar DLC system certainly allowed a very stable approach attitude, but having flown a few wide body a/c since the Tristar, I could not say that the difference is detectable in the cabin. From the pilot's point of view, it did allow a more rapid change of vertical speed during the approach, since lift was directly affected by spoiler deflection via a simple stick pitch input, rather than having to change wing angle of attack through a change in aircraft attitude.The system gave a rapid response in the go-round, with virtually no sink after the TOGA button was pressed.The secret of a smooth landing in the L1011 was to always keep some positive back-pressure on the control column, after the flare was initiated, until touchdown.This stowed the spoiler panels from the 7 degree null position to 0 and helped to cushion the touchdown, which could be really smooth. Any relaxation of the back-pressure, or forward pressure ( you don't really do that in the flare, do you?) redeployed the spoilers to ( or beyond ) the 7 degree position and could dump the aircraft on the runway.
To answer a previous question: yes, the Tristar could land on a 2500m runway and we often did that. As I remember, things became challenging around 2200m, depending upon weight. Landing on full length 09R at LHR after an air-test, admittedly a minimum weight, we used max autobrake to stop. There was no time to pull reverse above idle before we reached taxy speed and we had to apply power to taxy forward to clear at the old runway threshold (block 79). The ground roll was around 800m or less, you can check it for yourself. That said, most modern jets can pull up extremely quickly. Its a shame that the only thing that simulators cannot simulate is max braking, it is literally a breathtaking experience. The Tristar was a good 'stopper' and much better than the DC10, which was very weak in that respect. (Yes, I flew both)