The result made it three wins from three in pre-season and Hill was pleased with the attitude of his squad as they kept the winning habit after already downing Welsh regional sides Cardiff Blues and Scarlets ahead of the new Aviva Premiership campaign.
"I was happy with that performance," he said. "Rotherham have come here with a very big pack and they are a very efficient forward unit.
"I know they came here expecting to cause us problems so I was delighted with the attitude.
"After big games against Cardiff Blues and Scarlets, it would have been easy tonight to think all we have got to do is turn-up. It was a bit of a mental thing to make sure all the players were in the right frame of mind.
"Dean Schofield obviously did a very good job to get all the players going in the dressing room because that first half, as we came in leading 31-0, was a very clinical performance.
"There were a few mistakes, but overall over 80 per cent of that was highly efficient and to score five tries by half-time was good.
"We conceded a couple of tries so Phil Larder will be talking to the players tomorrow. But up until now we have been losing the ball a bit too much, we had lacked ball retention, but tonight we improved that.
"Our lineout drive was also good. At this stage in pre-season, going into the Bath game, we are reasonably happy with the progress. We can see as a team that, from last year, we are making progress."
Hill also hailed the impact of giant Number Eight Taulava who returned to haunt the club he left in the summer with two bulldozing scores.
"We have lacked that ball carrying Number Eight in our back row in the past and that is why we have signed the likes of Semisi," added Hill.
"At lock we have brought in Dean Schofield to add a bit more firepower in the drive and in the ball carrying.
"Semisi is going from strength to strength. I thought he might come into the club and take a while to adjust to the Premiership standard. But on the basis of his three games so far, he has settled into the club really well.
"He looks like a starter now for the first game against Bath on September 1 here at Sixways."