I do actually love (loved?) this game. Hopefully someone is paying attention. Copying here in hopes that some of these issues can be repaired so the game isn't at least actively worse for having this expansion 
"Installing this will actively make your game worse. The UI elements now require nearly four times the number of clicks, are nested to a ridiculous degree, and make use of ambiguous icons. Setting up your ship is very difficult, because the essential information on your engineering upgrades is nowhere to be found in the outfitting menu. You can no longer directly plot routes to your bookmarks, the process now requiring additional click through the much-slower loading system map.
Performance on a solid gaming rig was cut by approximately half, and the graphics look worse. The lighting and gamma is messed up, any many layers of rendering simply fail to render. Burning stations no longer have smoke, fire, and visible battle-damage, for example. Simple things like the green lights to guide your station exits are gone. The stars are all now white pinpricks instead of varied colors and sizes according to their star class. Nebula and stellar phenomenon are all faint-to-invisible. The gamma and brightness issues make a lot of text blurry, which causes eye strain and headaches. Your ships no longer ice over when running cold, or smoke and spark when running hot. The emissive portions of cosmetic skins for your ships look bad when they successfully render at all. I just cannot exaggerate how much of a graphical downgrade Odyssey is compared to Horizons. It feels unfinished, although I cannot fathom why an expansion would -remove- quality and special effects.
My cosmetic rewards for pre-ordering were not delivered, and the UI for cosmetics is currently bugged. The mission generation system is also currently non-functional: The new expansion has literally has nothing to do. The one "on foot" mission I was able to experiment with ended with a crash to desktop, and followed with an inability to log in again for three hours.
Do not purchase."
"Installing this will actively make your game worse. The UI elements now require nearly four times the number of clicks, are nested to a ridiculous degree, and make use of ambiguous icons. Setting up your ship is very difficult, because the essential information on your engineering upgrades is nowhere to be found in the outfitting menu. You can no longer directly plot routes to your bookmarks, the process now requiring additional click through the much-slower loading system map.
Performance on a solid gaming rig was cut by approximately half, and the graphics look worse. The lighting and gamma is messed up, any many layers of rendering simply fail to render. Burning stations no longer have smoke, fire, and visible battle-damage, for example. Simple things like the green lights to guide your station exits are gone. The stars are all now white pinpricks instead of varied colors and sizes according to their star class. Nebula and stellar phenomenon are all faint-to-invisible. The gamma and brightness issues make a lot of text blurry, which causes eye strain and headaches. Your ships no longer ice over when running cold, or smoke and spark when running hot. The emissive portions of cosmetic skins for your ships look bad when they successfully render at all. I just cannot exaggerate how much of a graphical downgrade Odyssey is compared to Horizons. It feels unfinished, although I cannot fathom why an expansion would -remove- quality and special effects.
My cosmetic rewards for pre-ordering were not delivered, and the UI for cosmetics is currently bugged. The mission generation system is also currently non-functional: The new expansion has literally has nothing to do. The one "on foot" mission I was able to experiment with ended with a crash to desktop, and followed with an inability to log in again for three hours.
Do not purchase."