Great job on this! It actually somehow has the feel of being much larger than it actually is.
You definitely are one of the up-and-coming MOC'ers on the CC forum, I'd say. Keep up this rate of improvement, and pretty soon you'll have the skills to be in the hunt for the CCC Master Builder award!
A few things to improve on:
Texture - this still seems to be a bit too busy in terms of all of the different textures you have going on. Maybe it's just a personal preference thing, but I think if you cleaned it up just a tad, it would help to accent the architectural features instead of hiding them. Maybe try to focus on 1-2 textural details instead of 3-4 (in this MOC you used log bricks, tiles on walls, plates on walls, rails above windows, multi-leveled black roof, etc.)
Scale/Proportion - Keep working on looking at the "big picture" with regards to how different parts of your MOC relate to each other. For example, do you really have room to comfortably fit the stained glass building AND a tower on top of your keep? Is the front door maybe a tad undersized? Does the bridge get a little lost due to the short span and height of the walls on it? Just a few things to keep in mind.
Rocks/cliffs - They look great. Lots of variation and good "organic" feel. Great job.
Waterfall - Looks really good. Those are tough to pull off.
Building techniques - You've incorporated a lot of great techniques, and I really like your door design. The angle of the fortress is also really cool, and helped you to maximize your layout, in this case, since you went corner-to-corner on the baseplate. The curved bricks used on the bridge are also super cool, but unfortunately are not easily visible.
Color - You did a great job of using a very balanced color pallet on this MOC. The touches of red and tan along with the blue water and brown decking of the towers all help to break up the monotony of a large, gray structure. I also like that you've mottled in some old gray, though I know that's a personal preference thing. I do it myself all the time, and I think it helps the stone to look more natural.
I hope that helps. Keep up the good work!