PSG edged past Slot's side on penalties on their way to winning the competition for the first time in the last 16 last season.
Liverpool were riding high at the top of the Premier League when the sides last met, but have endured a much more difficult second season under Slot.
The Reds sit fifth in the English top flight and had to come from behind against Galatasaray after losing the first leg 1-0 in Istanbul.
However, there was little doubt over the outcome once Dominik Szoboszlai levelled the tie on 25 minutes at Anfield on Wednesday.
Hugo Ekitike, Ryan Gravenberch and Mohamed Salah struck in the second half, while Salah also missed a penalty as Liverpool responded in style from being booed off after Sunday's 1-1 draw against struggling Tottenham.
"They haven't dropped their standards. It was hardly possible for them to improve, but they've been very impressive till now," said Slot on facing the French champions.
"But I think after tonight they will not look forward to playing against us too."
Liverpool won 1-0 at the Parc des Princes last season, completely against the run of play.
But the roles were reversed as PSG triumphed 1-0 at Anfield despite a much-improved Liverpool display in the second leg.
"We were completely outplayed away from home. I think we played a great game here at Anfield and in the end we lost on penalties," added Slot.
Slot's decision to rest a number of key players from the start against Spurs at the weekend paid off.
Salah was one of those to return to the starting line-up and netted his 50th Champions League goal after the disappointment of missing from the spot and a series of other huge chances.
"I think it says a lot about his mentality. He missed a penalty just before half-time and that was, of course, a difficult moment because after 45 minutes being 1-0 up was ridiculous if you looked at the run of play," said Slot.
"Then to come out second half and perform like that. A great assist to Hugo and the goal he scored was a trademark of him."