IItinary

Neither of those itineraries look very comprehensive.

Make use of the bullet train from Seoul to Busan that only takes 3 hours.

Seoul 2 days
Beopjusa 1 day
Jikjisa 1/2 day
Boseong Tea Plantation 1 day
Haeinsa Temple 1/2 day
Busan 2 days

Then to Daegu / Gyeongju (1 days) & a bus to Andong (1), Samcheok (1), Seoraksan (1) Danyang (1) Seoul/ incheon (1 days) Book the USO tour to the DMZ well in advance, & note it leaves at 7:30 am

http://upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Ktx_map_en.svg/400px-Ktx_map_en.svg.png

Note that the train station for Ulsan is well inland of the town, which is on the coast.

Hi

you misunderstand. We only have app. 12 days, so I have to choose one of the two plans. It seems like a lot to spend 3 days in Busan. Is it that interesting?

http://wikitravel.org/en/Busan#See

You could cut time in both Busan, & Gyeongju, which is kind of spread out. Busan is worth seeing.

You can't ask strangers for suggestions on what you like to do. Personally, I would not be happy seeing temple after temple after temple, so I would avoid that. But you might like that.

I like the hectic pace of cities and the night markets but maybe you don't.

Here is a website on Busan that is interesting:

http://busan.for91days.com/busan-index-2/

Note the vast fortress walls in ruins, the temple built into a cliff, the seaside temple, the huge fish market, and the unusual neighborhoods.

In Seoul, I would try to quickly get through the DMZ tour, Namsan, Gyeongbukgung Palace, Namdaemun Market, & Insadong. Forget Chinatown at Incheon. Not very impressive and takes 2 hours by train.

http://wikitravel.org/en/Seoul#See

Maybe a 1/2 day trip to Beopjusa if time.

http://en.wikipedia.org/wiki/Beopjusa

If you go to Iksan / Jeonju, don't miss Tapsa.

http://en.wikipedia.org/wiki/Tapsa

All of the temples I've mentioned are stand-outs. There around 6 major temples in Seoul, but Gyeongbukgung is the temple to see.