It makes me feel little to be in the company of such great minds... Instead of an argument about the pros and cons of RSS / RO it all padding the own back about being so rocket scientist. Cons of RSS / RO (reading this thread) - Choice and installation of the mod is tedious - mod dependencies are high - hardware requirements are high - needs a lot of fine tuning with parts, contracts and isp balance wise - mediocre mod compatibility (mostly balance) - everything takes a lot more time Pros of RSS / RO (reading this thread) - steep learning curve - high motivation on success - allows to move the game focus more towards simulation/reality - ? Sorry but reading the posts doesn't really show more Pros. I'd say that RSS / RO would be used a lot more if it would blend in better/easier with other mods or even stock. Right now it's a niche mod that, compared to FAR/DRE/TAC, doesn't add much to the game. It does indeed add more realism. Yet it adds it to the game where it doesn't add much to the game experience or even learning experience. Please correct me, but the basic requirements in comparison to stock-like gameplay are: invest more time and fiddle together huge rockets out of small parts or mostly use scaled or procedural parts. Yet it also needs almost every mod that is used with RSS/RO to be rebalanced (fuel, life-support, aerodynamics, part sizes, contracts) to allow a satisfying real feeling. But why? I'd wager to say that players can learn and enjoy a lot more from playing gameplay-elements originating from stock or stock-mod gameplay (logistics (with TAC), rocket design, (space)plane design, orbital mechanics, aerodynamics (with FAR), reentry problems (with DRE) etc.) than they can from playing with RSS/RO which basically makes a simplified simulation a lot more tedious. It might let the player feel more hardcore, yet it's seems to me a bit like running your bike on flat tires. You put in a lot of effort and time to get to the same effect (learning and having fun building and flying rockets) everybody else has. In the end you are free to do it, as every KSP player has to choose which mods or any he or she uses. Yet it doesn't make you better... just different. That's why I will start a new game (again as on every major update) when the next update is released and choose scaled isp/fuels over a scaled geometry though, as it is easier to implement and compatible what mods I use.