Odyssey is second paid DLC for Elite Dangerous. Commanders can now explore galaxy not only in Ships, or SRVs, but also on foot. Surface of planets becomed much more detailed and newly is possible land also on worlds with thin atmospheres. The possibility of disembarking from a Ship (or SRV) and moving on foot (in a first-person view) changes a lot in the way the game is perceived. Also possibility to encounter local NPCs "in person" brings to this game a sense of life.
Release day for this new DLC (for PCs only) was 19th May 2021. With previous experience was however expected that this day will be hard to play due unstable servers. And it really was quite rough start which fortunatelly is improving quite fast from that date. Is good to say that many things (troubled servers, low performance, buggs in missions, unoptimised UI, ...) were very far behind even pessimistic expectations and Frontier Development got heavy hit on the market. Also players reviews on Steam are mostly negative (1/3 positive, 2/3 negative) which resulted (except other things) in direct involvement of Frontier's CEO David Braben. Now Odyssey receives main patches each week at time of regular servers maintenance. Today was released Patch 3, and there were earlier released also few further hotfixes which solved critical issues.
My own experience was in last two weeks mostly positive. Patches already solved numerous issues including much better functioning of game UI. Some parts like for example map of galaxy now works much better when compared with (old) Horizons DLC (fast search, route plotting to bookmarks, missions areas or planets etc.). On contrary to this for example ships outfitting still waits for improvement. Frontier is also heavily working in improving game engine performance, but there they have long way ahead. Odyssey release for Consoles and planetary tech upgrades for Horizons players on PCs should come at Autumn this year, but is clearly obvious that especially release for consoles needs allot of further work ... I bet that Frontier really do not want to follow example of Cyberunk 2077 game in regards to its tragic performance on consoles which is still not solved after more as 6 months after release. Still, despite all these updates and fixes, it is now safer to consider Odyssey state as a "Beta" for at least next 2-3 months.
I'd say yes, but it really highly depends about your stance towards First-person shooter play and what PC do you have. On foot play on planets (open terrain, settlements, combat zones) will not have high fps even on latest graphic cards (in 4k), is reasonable expect at best 35-55 fps. There are ongoing rumours than next week patch should bring some bigger improvements in performeance, but I would be not betting on it. To give you an example: my three years old PC with 16 GB RAM, i5-8400 CPU and GTX 1070 Ti 8GB, have "on foot" in max graphic setting 35-55 fps on 1080p monitor without supersampling (set to 1). In Horizons DLC I had 2-3 times more fps and this is quite common situation amongst all players. Despite all these troubles I see Odyssey content as very refreshing. It have its own flaws, have really high grind potencial, but offer more time spent with gameplay, nicer views (especially when you were used only to the Bubble and everywhere dark space including horizons of the planets without atmosphere) and more different ways how to play this game, especially if you liked to engage in local BGS (background simulation) and are supporting chosen minor faction.