My may concern about this match is, as I have written above, that the pattern of the Berdych wins is mostly like that: he wins when he shouldn´t.
But, aside from intangibles, in their match at the AO, Federer shut the door on Berdych in two aspects: variation on the serve (Berdych used to read well Federer´s serve, but his placement and variety has improved), and a much more solid backhand. So Berdych had to go for an open contest and was completely overplayed. In Miami the story was completely different, Berdych raised his level, Federer was far bellow his AO standard and was lucky to escape. I do not think he will let this happen again, but the cold truth is that Berdych had a match point on their last match.
I´ve seen Federer start a bit too slow some matches in this tournament, but tomorrow I guess he comes out firing in all cylinders, trying to let clear who will be the winner from the get go.