With this wonderful video and great superimposition of both players it clearly demonstrates uncanny similarities between both.
It could be Dimitrov totally based his game on Federer.. or they are just equally talented
However when slowed down the video does show subtle differences and that also explains why Federer still look a tad more fluid in live action
1. Lag time in Dimitrov serve when approaching upswing
2. Lag time in Dimitrov forehand when approaching upsing