Buying a new acoustic guitar can be a joyful experience and we all know that sometimes there can be so many choices we don't know where to start.
Maybe the choice could be right in front of you the whole time or it can be hiding in the many sizes available. A lot of it has to do with your individual playing style. A question to ask yourself; are are you a picker, strummer or somewhere in between? The smaller sized guitars are generally for the finger pickers as they have a smaller top surface area, This gives you less 'overall' sound and as a result you hear more. You can hear the definition between a bass line and a melody much clearer because it is not muddied up with all the sound produced with a large top wood.
Great examples or these would be the Grand Concert or parlour sized guitars.The big guitars can help if you are a powerful player and need some extra space in the guitar to contain your strong hand, so to speak. Some examples of these would be the Grand Orchestra, Dreadnought or Grand Symphony sizes. These bigger guitars would be used for a Johnny Cash-style heavy strumming style.
A nice middle ground can be seen as the Grand Auditorium or mini jumbo shape which are great for those of us that enjoy finger picking as well and strumming along to our favorite songs.
The most important thing to remember is not to get to caught up in the specifications. Trust your gut and when something feels right and inspires you to play it is always a good thing. Too often we get caught up in the latest thing and lose sight of what matters...Play-ability!
So plug in or not and let the guitar do what it was built to do...Entertain yourself or others keeping in mind the number one thing on this green earth....Have fun!