i used wavelab 5.0a to do the wilco matrix last weekend and I was very pleased overall. the interface is pretty similar and the processing speeds overall seemed very similar to 4.0c. i had never used the montage feature in 4.0c, so i can't really compare the two. but moving around the files was very simple. and i could have the aud file open in both the montage and the wav editor at the same time. as i made changes in the wav editor (reducing gain for the aud portion), it was automatically changed in the montage section so that i didn't have to save, close and reopen. this was the first matrix I had done and while time consuming, I thought it went very smooth.