I used to use Acid Pro 7 but recently moved away for a few reasons
*It's not fully 64 bit compatible and hasn't had an update in over three years, there are a lot of rumors floating around on Sony's forums that development has been abandoned (two full new versions of Vegas and one Soundforge full version upgrade released since there was even a patch to Acid released)
*No track to track routing
*VST support is spotty and limited. You can only have one plugin open at a time which didn't work well for me when mixing, it just slows things down and makes tweaking more than one thing at a time on one or multiple tracks impossible. There are also some compatibility issues with some of the nicer VSTs that I wanted to use
*MIDI is fairly basic and I was outgrowing it
I don't think it's a bad DAW and Iloved learning music production on it and I hope Sony do eventually release a new 64 bit fully Win 7 version with better MIDI and VST implementation but for many it seems to be a dying platform
Just one opinion
YMMV