Apogee has released a new version of RockSim, version 10. For those that already own RockSim 9, upgrading to version 10 is free. In fact they are highly recommending that anyone that owns version 9 upgrade to version 10 as they plan to drop support for version 9. To do the upgrade, you will need your version 9 activation code and be able to log in to your Apogee account. Just go to the Apogee website and click on the links to do the upgrade. They have 2 videos to walk you through the process. Note that you will be basically trading in your version 9 activation code for a new version 10 activation code. Once you do this, version 9 will no longer work on your installed computers. I have upgraded and it went smoothly. The latest TheRocketryShow.com podcast (#89) talks about some of the new features.
I personally like OpenRocket better (especially because it is free), but I'm planning to buy Rocksim because it can accommodate more complex designs (fins on fins, pods, parallel staged boosters, etc.).
I have used both, but not extensively. The buzz about RockSim 10 is that it is a real improvement for doing complex rockets. The two programs are very similar in look and feel, and of course as mentioned, OpenRocket is free. (but then since I purchased RockSim version 9, RockSim version 10 was free for me as well!)
Last edit: 3 months 20 hours ago by guyw. Reason: missing "it"