Comparing the difficulty of the Osaek–Daecheong course to mountains near Seoul...

‌If you compare it to famous mountains near Seoul:
It feels roughly like climbing Mt. Buramsan Course 4 (a short uphill course) 4 times in a row...
Or like climbing Mt. Inwangsan 5 times in a row?
Mt. Achasan would be about 7 times in a row??
Mt. Dobongsan's Sinseondae would be like climbing it 3 times in a row?
For Mt. Bukhansan's Baegundae, you should count it as about 2.5 times..
That should give you an idea.
To be honest, the Osaek course doesn't have much to see in terms of scenery, other than the fact that it's the shortest time to reach Daecheongbong Peak.
However, if you descend toward the Sinseondae side, the view is absolutely stunning.
But because the distance is long,
beginners must manage their time very carefully.
What I mean is, start early... You must leave early if you want to descend before sunset.
Beginners should budget at least 12 hours for the Osaek - Daecheong - Sogongwon course.
Many people say they can do that course in 7–8 hours, but that is for intermediate hikers or higher who hike regularly..
Also, if you are traveling by public transportation, make sure to reserve your return bus ticket in advance.
There is a high probability you won't be able to get home if you don't have a ticket..
And the summit of Daecheongbong is extremely cold.
Even on a hot day, make sure to pack a windbreaker..