Hi, I'm a home guitarist that enjoys writing arrangements etc. I've used Home Studio 7xl for a while,
but am at a point where I can upgrade. But I don't know which version to get.
I write midi onto score rather than using a keyboard, and I'd like a good range of tools to do it.
I record guitar/ vocals at home but it's probably only going to be for home use.
Although I can afford the Producer version, I'd rather not spend money on a bunch of stuff that won't
get used. Is there anything in Producer that "I cannot live without?" VST's etc?
My other gear is a Quad-Capture and SM58.

If what you have is meeting your needs, you can "live without" either version. Anything beyond basics is typically more want than need. With that said, I think Producer is worth the want. As a vocalist, melodyne will be of great benefit. Yes the eq in studio is functional and good but the version in producer is much more useful. If money is not the issue, it is a no brainer imho.

Studio is pretty much the same program as Producer. Producer just comes with a few extra and it's impossible to tell what exactly you'll need without more detail so here is the comparison chart...
 
http://www.cakewalk.com/Products/SONAR
 
You'll see it is mostly just some extra instrument and effects but really many of them are quite useful and nice sounding. From there you can make a more educated decision but if you have questions abotu specific elements ask away. Many of use have been using it for a while now so have some insights. Do expect a massive change from what you own currently though. There will be a learning curve but it is worth it IMO.
 
Cheers.

Thanks for the quick responses. What 4 virtual instruments are in Producer and not in Studio? Are the XLN Drums a must have compared to Session? And finally, I'm a pretty awful vocalist, I'm not epecting Melodyne to make me sing like a nightingale, but is it that good?

Melodyne Essential is included in both Studio and Producer.
 
A detail list of what each version includes is here http://www.cakewalk.com/Products/SONAR/Versions
 
I guess the difference in instrument count are Addictive Drums, the 2 AAS synths and True Pianos Amber but the full versions of DimPro and Rapture are significantly better than the lite version included with Studio. Addictive Drums is a better drum synth than Session Drummer or Studio Instrument Drums. However Addictive Drums uses proprietary drum kits ony available from XLN. Session Drummer can load any samples in wave, aiff or ogg format.
 
There are also differences in the bundled ampsim which may be of interest. Studio bundles TH2 SONAR http://blog.cakewalk.com/...2-sonar-from-overloud/ . Producer bundles TH2 Producer http://blog.cakewalk.com/new-in-sonar-x2-producer-scorching-tones-and-killer-effects-with-th2-producer-from-overloud/
 

If you plan on using you're own vocals, it would be worth it for the Melodyne. Not sure about AD, as I don't use it. But quite a few people here seem to like it.

I think the session drums will work and if you feel they are lacking down the line, you can upgrade or get a 3rd party software, like Toontrack EZDrummer.  Melodyne is an excellent pitch correction/altering tool, but unless you become comfortable with the program, I think you'll spend more time "tweaking" and you could just do another take, punch in, comp vocals, or whatever... in much less time.  You can also get *creative* with Melodyne, but that's another avenue.  The other instruments shouldn't be deal breakers if you don't have them either.
However, the producer edition is a great value with the extras, but that's also why Cake probably has their products tier'd out in this manner.
I just jumped from 7PE to X3...have a decent amount of experience, but have a bit to go to feel *at home* totally with the new X3.  It's a massive, incredible program, as are their lesser costing ones.  Plan on learning for a bit, but when you're comfortable, your final results will really reflect that.
My opinion is that it's really the $ at this point that will probably dictate what you might get.  You'll be buying stuff now for the producer edition that you may not use immediately, but by the end of summer, you'd probably be glad you had them.  If you're a total newbie, I wouldn't waste the extra $ on the more expensive program at this point.  Upgrade when Cake puts out a new release... X4 or whatever.

The biggest problem I had with Session Drummer was a lack of velocity layers for the nuances I like (but for most basic-semi complex drum stuff it's fine) and the fact it didn't seem to play nice with my pad based controller.
 
However those problems were quickly remedied by purchasing the Andy John's kit for Session Drummer and there are a plethora of kits available for it produced by an excellent company called Platinum Samples.
 
Addictive Drums is a REALLY excellent program though and comes with much better kits that the base version of Session Drummer does. It also has more functionality within its internal mixer than SD does but if you know how to mix drums well already then you could technically accomplish all you need to with Session Drummer and just mixing the individual tracks normally in Sonar.
 
So... Session Drummer is definitely useable if you aren't going for some really intricate/hyper realistic stuff or are willing to buy some expansion packs for it but even Session Drummer at its best with expansion packs isn't as good as the base version of Addictive Drums in my opinion.
 
You could of course always purchase Studio and see how it floats you proverbial boat then upgrade to Producer if you feel you need/want more. I'm not sure if it would cost you any extra that way though so maybe someone else could chime in.
 
Cheers.

As the others said, Producer mainly comes with a bunch of extra instruments and fx. As a bundle, they're quite good value, but if you're not in a position where you'll use many or most of them (yet) there's no need to spring for them now. Apart from a few of the ProChannel modules (and the QuadCurve EQ Flyout), you could buy what you need from third party developers as well, and build your own collection to taste. You may end up doing that anyway even if you get Producer. I would rather spend 150 extra bucks on the Melodyne upgrade than on the other features in Producer, but I already have some third party stuff I prefer to the Sonar offerings.

Is Melodyne the same in both?
And would Studio give me enough to produce a small orchestra of instruments?
I feel I need to give you a bit more info, I'm also getting a laptop to run it. If I get Studio, I put more cash to the laptop and vice versa.