I agree with Mikey. Anyway, high action is not ordinarily a reason to replace a guitar. A setup shouldn't run you more than $35 or $50 usually. Having a guitar that is uncomfortable to hold is another matter, but you needn't buy a 3/4 size guitar just to get a smaller body. Look at some O, OO, or OOO/OM size guitars before you make up your mind. And maybe get that setup done, since uncomfortable action can color one's impression of everything about a guitar. I don't know what you have, though, so hard to say whether it's worth putting money into.
I'd stay away from the children's/travel sizes, though, unless you actually DO intend to travel frequently and a full size guitar (which in guitar-speak means full scale length and has nothing to do with body size) would be a problem. Reducing the scale length of a guitar means that your string tension will be lower at standard pitch, which is not a good thing in terms of volume or sound quality. Even a well-regarded travel guitar is not going to measure up (no pun intended) to a normal scale one, if all other things are equal. That's the sacrifice you make for extreme portability, or to get a guitar the right size for a kid of about 9 to learn on. And as Jonathan points out, in the case of the GS Mini, you would be paying two or three times what a similarly constructed guitar, even a normal scale one, of a less prestigious brand would cost.
Here's another idea - check out the very reasonably priced ($200-300) Yamaha 700 series. They have solid spruce tops, come in a dreadnought and OOO size, and sound astonishingly good for the money, especially if upgraded with a bone nut and saddle, which any guitar tech can do. Although they're often recommended to beginners, after doing a setup and nut/saddle replacement on one I found at a pawn shop, I'm finding it so much fun to play that I don't want to sell it just yet, even though I've got "better" guitars available. Alternatively, Seagull is often recommended as a midrange instrument that is well built and offers good value. Can't say I care for their sound, but YMMV.