When I was researching for my first DAW I stumbled across this forum.
 
Judging that rading a selection of posts on other DAWs was probably a good idea to get real world examples of issues, I hastened back to Sonar and immediately placed my order.
 
I wouldn't shift from Sonar now, no matter what was on the market. The software isn't perfect - nothing is - but I haven't had any show stopping bugs for a very long time. 

IT's the most feature rich DAW for your hard earned dollars. I don't think anything can compare. With other DAW's you buy the core and then fill it out with other purchases. Sonar just has everything you need to start from scratch and compile a professional sounding product without spending another penny.
 
All the other things mentioned in the thread are true, but for me it was getting the most options while putting out the least amount of money.

I use Sonar because it is the best recording software I can find for the money!

5. The look. I like the way it looks. Of course appearance is subjective, and the third-party plug-ins contribute to a "designed by committee" feel, but I find the core program visually inspiring.

 
This is an interesting point that doesn't gets much traction. I agree with this point completely. I also like the look of Sonar 2015 Platinum. 

bz2838
I use Sonar because it is the best recording software I can find for the money!

Can't argue with that!

Can I add another welcome and mention that this forum is such an advantage that it's not an understatement to say that it is one of Sonar's top features.

The reasons why I use it are pretty much covered in the other answers. The reason why you should use it is that here on this forum we have scook, who is like your own personal reference guide - ask any question you like and he'll not only know the answer, but has usually answered it before you finished asking the question, lol !  That and the fact that it seems that you're already buddies with Anderton, who also seems to have some degree of knowledge ;)
 
 

Can't help mentioning some noticeable differences between Sonar and S1, and why I prefer Sonar...
 
1. S1 v2 came out more than 3 years ago, and recent patch releases contained only a handful of enhancements/fixes. The development has definitely slowed down.
 
2. S1 has a showstopper bug that messes up track colors when using multi-out soft synths (and it's not fixed for more than 3 years). This stopped me from creating any new project in the daw.
 
3. The quality of time-stretched audio is better in Sonar. I did a few tests after upgrading to Platinum, and especially the Radius Solo algorithm in Sonar is great.
 
4. Sonar has a LOT more features.
 
5. Sonar looks beautiful and professional.
 
6. Sonar forum is just amazing. 
 
Edit:
And also...........S1 doesn't have a MIDI panic button.

For a beginner the question is tough. It takes such a long time to learn one DAW so well that you really can form an opinion about it, that joggling between several demos can be overwhelming.
And when you learn  the basics of your "first one" you easily take it's workflow as the fundamental method, and testing other DAWs may then cause a lot of confusion due to different features.
Cakewalk came to me with my first proper soundcard. I learned it little by little,  upgraded and spent litterally hundreds of hours reading the (then 900 pages, now 1800 pages) manual. I got some version of Cubase with some other soundcard  but after a day or two of testing I did not spend any energy on it simply because I had no need to.

iv only just recently started using computer based music  decided on sonar & as stated above i think without the help of these forums i would have given up months ago....i am gradually understanding it with the help of these guys & groove 3 starting to make MUSIC (cos thats wot its all about)....good luck & as i said u cant go wrong with Sonar