The Church of the Good Shepherd is the most photographed building in New Zealand. The village at the foot of Aoraki/Mount Cook is the actual mountain. They are 70 minutes apart, in the same region, and the difference in what you experience is enormous.
What you actually get at Lake Tekapo
A small lake town, the famous church (which you cannot enter for most of the day because the queue is 40 minutes long), a hot springs complex that was sold to Chinese investors in 2016, and a Three Wise Men and a million Instagram photos. The Mt John Summit walk (covered separately) is the actual reason to be there. The town itself is a stop, not a destination. If you go just to see the church and take a photo, you have wasted 3 hours. If you go for the summit walk and the observatory café, you have had a good day.
What you get at Aoraki/Mount Cook village
The actual village at the foot of New Zealand's highest mountain. 27 km off SH8, the road winds up the Hooker Valley and terminates in a small settlement with two hotels, a visitor centre, a DOC office, and not much else. The walks start from the village: Hooker Valley Track (3 hours, easy, glacier views), Kea Point (1.5 hours, easy, mountain views), and Sealy Tarns (5 hours return, a steep climb with around 500m of elevation gain, the best mountain view you'll get anywhere in the park on foot). Tasman Glacier viewpoint and boat tour is 45 minutes from the village. Stargazing at the Aoraki Mackenzie International Dark Sky Reserve is from the village car park. The village is where you stay if you want to climb, tramp, or sit and look at the mountain.
The honest case for Tekapo anyway
If you are on a tight South Island loop and need somewhere to stay with a supermarket, restaurant, and petrol, Tekapo is one of the larger towns in the Mackenzie. It has a Four Square, two decent bakeries, and a Thai restaurant. As a base for the region it is functional. As the destination, you are going to be disappointed. The 70-minute drive to Mount Cook village is one of the best drives in the country. Skip the town centre, drive to the mountain.
The bit nobody publishes: real time and cost
Tekapo: free to walk around, 30-minute stop, plus the Mt John Summit walk if you want it. Aoraki/Mount Cook village: free to enter the national park, walks are free, the only costs are food and accommodation. The DOC campsite in the village (White Horse Hill) runs NZD $32 per night. Hotels run NZD $200 to $400 a night. The same Mount Cook photo that everyone takes in Tekapo is taken in Mount Cook village, except you can stand in the same photo instead of watching someone else take it.
How to actually do Mount Cook
Drive in on SH80, turn off at the Aoraki/Mount Cook sign. Drive the 27 km to the village. Park at the visitor centre. Do the Hooker Valley Track on arrival (3 hours return, flat, all bridges, no real climbing), drive up to the White Horse Hill campground or one of the hotels for the night, do the Kea Point or Sealy Tarns walk the next morning, then drive out. Two nights is the right amount. One night and you will leave wishing you had stayed longer. If you are pressed, do Hooker Valley and drive out the same day. Just go.
View on map
Aoraki / Mount Cook · coordinates -43.735, 170.105