What are you planning to record using whatever software you choose? I've seen posts by people using Vegas around here, and it does a fine job for audio. I've used Vegas previously for recording audio. I like Sony's software myself - have owned and used Acid, Vegas and Sound Forge. If that's what appeals to you and can help you with workflow, go with Vegas. Of course, there are many other options too: n-track, magix, tracktion, etc. If you're interested in other options, search around here as they've all been discussed.
Sonar's interface may be cumbersome to some, but I use it and I can get around just fine. For me, I've gotten to a point of a good workflow and have been pleased with the functionality and features. The Cubase interface is similar, but to me, it didn't seem as "cluttered". Looked a little more laid back (for lack of a better definition). I just had to move from Cubase because of various issues that I just couldn't get resolved. It is definitely not a bad program, I just found something that fit my needs better and wasn't as picky with my system.
Hope I didn't stray too far as this is the Cubase forum...
