The 29-year-old has revealed the move across the border fulfils a long held ambition and how he plans to make a big impact for Mike Ruddock's men.
"It is a bit of change for me, but one that I really wanted having played Magners League for several seasons," said MacRae.
"I was ready for a new challenge and a change of circumstances. The opportunity came up to play in the Guinness Premiership and trial with Worcester. I really wanted to take it so I'm delighted to sign the new deal.
"It was something that I had aspirations to do, having spoken to a lot of the guys who I have played with up in Scotland who have tried it.
"It is a different brand of rugby compared to the Magners League with regards to the relegation, it makes it more intense."
MacRae has featured in two pre-season games for Warriors and has already been impressed by his new team-mates.
He said: "There are some big names behind the scrum with Chris Latham, Rico Gear and Sam Tuitupou. These are guys I have seen on the television playing so it's great to now be around them.
"There is a very competitive environment in the squad. The first hurdle is done, I've signed and the next thing is to stake a place for a spot in the league games.
"I hadn't met Mike Ruddock before I joined, but I heard a lot of positive things about him - he has lived up to that. He has been very welcoming and done everything he could, along with Alun Carter our Team Manager, to make sure I settle in properly.
"The players have also been very forthcoming and helped me settle in - not bad for a Scotsman coming down to England!"
MacRae, who has featured for Scotland Sevens, has representative honours for Scotland A and been part of the senior set-up, had endured a stop start two years at Edinburgh.
But he joins Warriors fully fit and keen to hit the floor running to try and impress everyone at his new home.
"I had a mixed two years at Edinburgh, I was in the World Cup training camp for 2007 but at the end of that I had to undergo an ankle operation which scuppered the start of the season," he said.
"Last year I had a good pre-season but then picked up an injury in the gym. I'm just keen to get rugby back in me. I played some stuff the end of last season with Edinburgh but I'm looking to come down here and see it as a fresh start.
"I'm motivated for myself to get going but also for this club, I want to do well for Worcester and have really bought into the club.
"I couldn't be in a better place to play rugby, the facilities here are just spot on," he added.
"My first impression as I drove down the M5 was fantastic. To be at a club with its own stadium is huge. At Edinburgh our games were at Murrayfield and so we were getting crowds of between four and five thousand in a big stadium.
"Here it feels very different. Even being involved in the first pre-season game with Doncaster, the crowd were very verbal.
"Speaking to the guys they were telling me how great the fans are here and how they really get behind the team home and away, they really make some noise. I'm now really looking forward to a full house and the atmosphere at Warriors."