Its kind of a null argument. Its like saying what exactly makes a certain beautiful women attractive? Is it her eyes? Is it her Lips? The way she moves? The way she thinks? The answer is, that as always, its a combination of factors. But in this case, perhaps its because this particular "woman" is new and open: unfettered by the past, and rife with possibility in an uncharted future. As you say, anything can be rewritten, and all sorts of things can be tacked on, but there is fantasy, and there is reality. Raise your hands, those here who think its likely to happen any time soon. I guess you could say, I have a pattern. Years ago (2012), I was the one who initially began lobbying for Sundog to be included in X-plane, posting videos and demos from your site, starting threads, discussing possibilities, much as I discuss Outerra, now: and pushing on the Avsim forums when the product was finally announced. You want to know what the general reaction to my initial posts was? From many it was that the pictures were pretty and all, but that the existing clouds where fine. No need to change perfection, "I see nothing wrong with the current clouds, etc....." status quo, essentially. Yes, as you say, "How those (Outerra's clouds) are done are also pretty well understood" but of course thats not the whole story. Its overall execution, and eventually features thats the key, or your own product would have no market over X-plane default! I've been here before! Years earlier, when I was on the Aerosoft site, pushing procedural engines, showing how roads could be pulled from Osm data, and how they needn't be flat ribbons painted on the landscape given the power of modern computers..... You want to know what the reaction was then? Yup! "I'm a flight simmer flying a plane. Who cares about roads!? FSX roads are fine" Pulling resources from important things..... etc. But. Lets get to the specific question of what makes Outerra impressive to me personally, I would say that yes its the fractal terrain, but its also the malleability of that terrain. The ability to change it on the fly. Change the geometry with a click. To move roads and eventually rivers and mountains and to eventually repaint (Splat) the landscape in real time, putting into the individual users hands the ability to easily recreate their own areas with an ease we can only imagine now. Lake missing near your house? clickety click click, lake is added, back to flying. Big open void that should be a shopping center? At the top of a hill? With a road leading up to it? Click click..... ten minutes later back to flying. Want to add your house? No need to even close the sim. Click, click........ Its the possibilities, that are impressive. Its the entire package all together, both now, and what it could be. Its the reduction in space requirements due to the way the program uses textures: the ability to seamlessly zoom from orbit to centimeter level individual blades of grass: the eventual ability to fly far beyond earth. The openness. Its the excitement of something new in the simulator scene. Its that Outerra is a whole world and not just planes, but potentially a boat simulation and a car simulation and a train simulation and..... whatever the designers can imagine; not static, but living and open, and something we as a community can get in on the ground floor of and influence to the better at a time when civilian sims are becoming rare as dodo's You asked "Do you want to lobby LR to focus XP11 on visual improvements, or other stuff, given their limited resources?" I've encountered that same argument several times, first in X-Plane about the clouds, and later, the interface, both of which have indeed changed. The question as stated seems to assume the two options are indelibly exclusive, as if LRs resources, intent, and focus are indefinitely stagnant. Not the most optimistic assumption, but in any case, my answer would be that LR will do whatever they choose to do of course. What I'm doing is simply what I have always done and what the op suggested; explored and imagined possibilities, discussed potentials, and dreamed about the future. Concluding. As I've said earlier in the thread, I consider any action from LR itself to be both unlikely and not necessarily efficient. But, much like the case of your own program, its best never to underestimate the ingenuity of outsiders with an idea, the skill to implement it, and a bit of patience/perseverance. Could be some guy in his livingroom, beavering away at it as we speak. Edited for lottsa' of spelling errors, cause I suck!