A Wales tournament win did not look likely after an opening 30-22 defeat to Ireland - an eighth loss in a row - but victories on the road in Paris, Rome and Edinburgh brought stability back to the side.
Now the goal will be to prove themselves against one of the big three South Hemisphere teams, and Roberts believes there is plenty more to come from this Wales team.
"I think there is more to come - that's the scary thing," he said.
"Our defence is outstanding, there is more to come in attack, and competition for places is very good in the squad. That is what drives us forward as a team.
"To concede just three points against a team of England's potency is very, very good for us and a tap on the back to Shaun Edwards.
"From a personal point of view it's been an absolute privilege to work with him. He's a great character, he knows his stuff inside and out, and to learn from someone of his calibre is up there with one of my greatest experiences as a rugby player.
"To see him smiling at the end was very pleasing. It's a better buzz than last year, if anything, because our games have been built on solid grunt and attitude."