In my opinion, the Skyrim world is a LOT better then Cyrodiil. I've heard the Cyrodiil map is larger but:
- Cyrodiil is more 'cartoony' and has a more 'idealistic' Renascence feel... Reality is, back in the day of horses and sword play (at least in real human history) things were dirty, violent, and unsanitary. Skyrim has a much more 'realistic' feel to it (which is my preference).
- Cyrodiil had dungeons and caves that all looked alike and, after a while, even with the best role playing intentions, made it difficult to 'care' which new place you found since they all looked the same with the same worthless leveled loot
- Cyrodiil cities were too similar for the more part.... sure some had snow, other were in the marsh, some were on the coast... but they didn't seem to have any unique character to them
- Skyrim's graphics and weather system is so much more immersive. There are time I seriously feel like I'm getting chilly when I'm trekking in Northern Skyrim and the snow and wind are blowing so hard you can hardly see
- Skyrim's harvestable ingredients disapear after picking them!!! Makes it easy to know what you picked and what you didn't.
and last but not least.....
NO FRACKING OBLIVION GATES :intergalactic:
The Cyrodill map is not bigger, its about half the size. Try this test, make a fresh character in oblivion and run from the very bottom of cyrodill to Anvil using a straight line technique, it shouldn't take you more than 10 minutes depending on combat situations. Then load up Skyrim and try running from the southeastern most portion of the map to the northeastern most point, again the longest stretch of map, do this without sprinting or using a horse. For me, the difference was astounding, it took me nearly 45 minutes to go from one end of Skyrim to the other without sprinting.