Here is an interesting article that talks about the different sizes of acoustic guitars and how they may be used best (setting, style).
Personally, dreadnoughts don't appeal to me because they are so loud, so uncomfortably large, and they are "too full" sounding. I'm more interested in fingerstyle, and the smaller sizes are more suitable for that. I bought a parlor guitar that I hope to get by middle of next week. Parlor isn't a standardized size, but basically it's about the size that people referred to when they said "guitar" before the first world war. Then guitars just got bigger and bigger, presumably so they could compete with banjos, volume-wise.
The one I bought has a 24" scale (shorter than this and I feel that standard guitar tuning won't work and you have to tune it up), with a relatively wide nut (1 3/4") for an acoustic guitar, and it was relatively inexpensive. It's this one here (without the pick guard as the new ones don't have it, luckily):
I think this is as big and as loud as I want it, and it has the right sound. I'm conditioned by several years of playing and listening to ukuleles, so the "spammy sound" of larger guitars is almost uncomfortable to my ear. I looked at OM/folk sizes, whose bodies are a bit bigger and the scale is around 25.5", and I found the sound to be too full already with those. It would work for me, but the parlor size's sound texture appeals much more to me. I also think the 24" scale will be easier to play - less string tension. Plus I think 12 frets to the body is perfect. Certainly prefer my 12-frets-to-body tenor to the 14-frets-to-body ukes I had.
If I'll get on with it in the long run, I don't know. I just wanted to experience steel strings. I also plan to apply the lessons I learned from the ukulele journey here and not repeat the same mistakes: stick to something that costs between 300-700, buy one properly set-up instrument only and then play it for at least a year before thinking about replacing it or getting a second one, embrace laminate sides/backs to avoid fretting over humidity (with a solid top), remember that skill is my chief limitation (not the instrument), replace strings only when new ones are needed, don't buy too many books, be patient with myself.