I have both. I've used Home Studio 2004 for 8 years. I just started with Pro Audio 9 last night. Which does anybody prefer and why? I want to use the best. Once I downloaded a free trial of Sonar, and it confused me. I could learn it later, but just not now while I'm finishing up a degree.
 
But I have to create music projects for school. I'm wondering if Pro Audio 9 has some advantages.

Found this on another thread:

To Enter a Triplet in pro audio 9:
1.         Turn on the Snap to Time option.
2.         Click the Draw tool.
3.         Click the appropriate notehead button.
4.         Select the Triplet option .
5.         Enter the first note at the desired location in the staff.
Cakewalk inserts all three triplet notes at the same pitch. You can then drag the second and third notes to their correct pitch locations.

It works even better, though, in Home Studio 2004. The existing notes in the track do not change value like they do in Pro Audio.

I've never used Pro Audio 9, Have always been pretty much all audio recording, no midi, so can't give any opinion on any advantages or disadvantages there.
 
Home Studio 2004 is based on Sonar 2 and is about 4 years newer than Pro Audio 9, as far as audio related features go, Home Studio 2004 has at least two things going for it that bring it out of the dark ages of pre Sonar 2.2 Cakewalk software..
 
HS 2004 can use WDM/KS and ASIO soundcard drivers, both lower latency and input monitoring are possible if drivers and computer are capable, even if the latency is just a little too high and direct monitoring from the interface needs to be used, it is usually possible to setup a usable software reverb for monitoring purposes while tracking audio, eliminating the need for a hardware reverb.
 
HS 2004 also has "Per Project" audio folders, using these as your default setup makes project backup and portability incredibly easy without the need to use bundle files which condense your recorded audio files, I would prefer my original audio files to remain intact, I usually will only perform destructive editing/processing on copies only.

Pro Audio seems more simple, though, and so is more reliable and stable. It runs without any hangups. It would arm for audio when Home Studio would not. Right now, it will record my midi while Home Studio will not.
 
So I think Pro audio is a good back-up. 

"It works even better, though, in Home Studio 2004. The existing notes in the track do not change value like they do in Pro Audio."
 
I think I'm wrong on this. I just tried it again and it changed note values of notes in other measures. Yesterday it didn't. Today it did. Not sure what's going on.