do you guys think it's worth getting Sonar professional?

I have learned my way thru 5 to MC7....my current daw and have at times wondered if I should take the Sonar plunge.   But I usually just slow myself down  and realize MC7 is taking care of all my needs for recording with plenty of plugin capability (of which I use plenty)as I still learn and practice as I write/record/mix. 
I find  MC7 is reliable and consistent and I don't think its a reasonable move for me at this time to begin to have to learn all the nuances/diff's between MC7 and Sonar (though i suspect i would figure most steps similar...).....ie it will slow my current workflow.  I do wonder at moments if Sonar would afford more efficiencies in the long run ...though surely I wouldn't really know personally unless I cross that bridge to begin learning its curves and locations of needed things.  
 That said.... I guess it really comes down to your personal goals with it.  If MC7 is getting your recording/mixing needs met...likely no need to switch trains.  The Sonar train is enticing....but I am happy on my current track/journey and views  ;o)   Good luck....I do look forward to that new rail system someday...but my main goal/focus is the music at this time and MC7 is rolling along well with me.   
 ps....love to hear from ya if ya do jump to Sonar and share what ya liked better (hopefully lots ;o) )  
 EDIT:  I meant to add....at this time also....I don't think Sonar would give me any better "Recording" results vs MC7 ....so that right there does not warrant a "need" to slow my flow and switch .  I am EXTREMELY happy with the results I am getting.   I am recording with my drumming pal and will be bringing more players together...band intentions....as we write/record originals and covers.   

That's a great point. I am liking MC7, I like the extra editing tools and possibly sounds the Sonar has to offer. I am looking at getting Melodyne Essentials which costs $99 but I pay a little more and get Sonar Pro with a bunch of extra stuff including Melodyne.. I did see Melodyne on Ebay for $49 though.  I like the Sonitus reverb so far which is included in MC7 and and thought maybe some of the other Sonitus effects or plugins included In Pro might be awesome. Maybe I can find the whole suite elsewhere. I do want more sounds to play with although I do have a lot of sounds with MC7. I don't know. maybe I would like Rapture or Dimension  Pro. Man, so many decisions. I could spend $1000 or more easily if I was impulsive. Max them credit cards out lol.  But I'm not. It might overwhelm me having all the extra stuff too. I'm thinking I might just get Melodyne and play with what I have.
 

Wow, that looks great and very affordable. I may just buy that. Seems to have some extra goodies and sounds for a great price.

Also, Would it open the songs I have been working on in mc7?

http://www.guitarcenter.com/Cakewalk/SONAR-Platinum-Upgrade-From-Any-Previous-Version.gc     Does Music Creator 7 count as a past sonar for upgrade? $299 would be great

It all depends on what you're after, just the DAW or DAW + accessories (goodies).  Below is a link to comparison charts between the three editions of Sonar; Artist, Professional and Platinum.  The DAW is the same in each but each edition includes a different list of accessories with Artist the base edition and Platinum top-of-the-line.  Cost wise, you will be working from the "I am new to Sonar" list as Music Creator is considered a Cakewalk, not Sonar, product.
 
http://www.cakewalk.com/Products/SONAR/Versions
 
Cakewalk and Sonar had a product called Home Studio in the past so it's easy to get confused but the Home Studio I linked to in my post above is completely new.  Home Studio (I'll call it Home Studio 2017 to avoid confusion) will replace Music Creator once Music Creator is no longer offered.  It has more capability than MC7 which in turn has more capability than the MC6 I have.

Check this out for $ 34.99  https://www.cakewalk.com/.oducts/SONAR-Home-Studio

jimfogle

abacab
Check this out for $ 34.99  https://www.cakewalk.com/.oducts/SONAR-Home-Studio

The $34.99 sale ended yesterday, 12/09/2016.  Unless Cake extends the sale, the price is now $49.99 which is still a great price.

That's what it says, but when I click on the buy link, it still goes into my shopping cart for $34.99

I'll just jump in here. I have used all the versions of Sonar over the last decade. I started with Guitar Studio and then I got Home Studio with a Sound Canvas. That was 2004 I guess looking at my join date here. 
The first versions up to 8.5 all had more or less the same interface and GUI. It's always been a case of adding more features and VST's as you spend the money. 
Things went for a S__T with X1. So I waited that out until X3 when the forum calmed down a stability returned. 
I still have not fully come to grasp with the new interface.. I have the latest and greatest version and yes for life, of Platinum.  But, I like you folks here like things basic and uncluttered, so I just bought the new Home Studio on sale. 
 
The interface is exactly the same as the bigger versions. But I love it's simple straight forward no fancy pants approach. Yes the full versions come with a tonne of great VST's and plug ins. But look at the list and deside if you really ,really need them.. Your paying $400  for the same software as HS but getting a lot of stuff. So if you don't need that stuff then there you go, There's lots you can gather for free and on sale. 
Because the included SI drum kit sucks I just bought the Air software Strike 2 drummer VST for only $43. It blows away Sessions drummer.
 
Anyhow what you have to do is take a hard look at the list that compares the features with each version of Sonar and decide what you need and what you don't need. 
 
I'm really loving Home Studio which I installed on a Laptop and I'm busy editing some midi files with just the WASAPI driver and a set of cheap cans. 
I could record just about anything with this rig ( with an interface of course) and it would sound just as good as anything I recorded with SPLAT. 
 
 
 
 

I started with MC4 got 5 and then got 6. Cake offered a crossgrade to Sonar 1 essentials when it was out and at a no-brainer price, so I jumped.
 
Here's the deal. If you like what MC can do, all you need to do is add the VST's you want and keep on recording.
 
I used Melodyne and Ozone in MC 4. I turned out some decent tunes with it. My tunes are getting better sounding but it's not because of Sonar. It's because I'm learning more about how to record and mix better.

If you "just gotta" go to Sonar, I'm not going to tell you not too.... make the move, but learn the program, the add ons, and learn how to record and mix.