The Aviva Premiership leaders' 27-16 victory over Ulster was secured through tries by England wing Chris Ashton and England back-row hopeful Will Fraser. Fly-half Owen Farrell kicked 17 points, with Ulster reduced to a late Iain Henderson touchdown, plus three penalties and a conversion from scrum-half Ruan Pienaar.
"They were probably the best team we had played all season," said McCall, a former Ulster back. "For us to be 27-9 up with five minutes to go says a lot about the quality of our performance."
He added: "We've worked unbelievably hard, especially defensively, where we were brilliant throughout the match. We took our opportunities.
"Twelve months ago we were very disappointed with how we coped physically against Clermont Auvergne in the quarter-finals, but 12 months on we believed beforehand that we had moved on, matured as a group and were a better team.
"The players have an unbelievable work ethic for each other."
McCall also paid tribute to Ashton, who lost form drastically during England's RBS 6 Nations campaign but whose second-half touchdown put Saracens out of sight.
"He has had a lot of stick," McCall added.
"But the last three weeks for us he has been exceptional. He took his try magnificently today - it was a real finisher's try - but he had a great game apart from that.
"We defended really well, we were good at the breakdown and forced them to play most of the game from their own half, and when we got into their 22 we generally came away with something."
- Sports & Recreation