To generalize the answer your question, Yes, The OC has a better scale range for encounters, and treasure generated, than SOU. The in debth answer is, its all about the story of the SOU. It is set in a remote part of the world, not a big city. Though your character is suppose to start at level 1 for both, by the time you move onto part 2 of the OC, you can be 10th level or greater, by the time you move to part 2 in SOU, maybe level 4. part one of SOU has 38 areas you can access. The OC, 112. There are loads of side quests in the OC, all of which give even more XP, while SOU, has just a couple. As far as SOUs difficulty, I did not have a feeling of it being boring, but I admit, I was enjoying the story of it more than the action. When I got into the last chapter, I even found it to be rather challenging, as my Character had taken one of the new Prestige classes.
A second note on the treasure distribution of SOU. SOU introduced a new treasure system, making treasure generation extreemly customizationable for builders, rather than the standard OC script way. I use the SOU type treasure system in everything I build now, because I do not have to worry about the wrong thing showing up. For instance, the OC way, you open a placeable and the script fires, now it does its thing, and then looks at a list of possible treasure to create, and if you are lucky, you can get something ridiculous for a level 1. say boots of speed. Now before everyone screams that boots of speed are not ridiculous, they are acceptable items to have, for a level one, generating level 1 encounters with level 1 type creatures Boots of Speed give a unfair advantage to the the player, making the game too easy to get through. (course its a mater of preference). The other thing that this changed was it helped keep creatures from droppping impossible extras on death, like the rat that dropped platemail, or the beggar that dropped a +1 sword worth 100 gold. SOU changed this by allowing chests to be placed out of accessability of the player where the builder could place only the items that he wants to be found.