It's six months since the three South Korean mobile operators simultaneously switched on the world's first nationwide 5G networks.
Here's what worked, what didn't and what is still a work in progress.
Customers like it
At least, judging by the 3 million who have subscribed in the first five months.
The availability of good phones from day one has been an obvious improvement over previous new-generation networks.
Even more appealing than the choice of three Samsungs and an LG has been the price. SKT, for example, is offering 150GB at KRW75,000 ($62) while KT is selling unlimited packages starting from KRW80,000 ($66).
But the take-up rate also shows consumers love a good subsidy -- to the point where the regulator had to call operators to remind them of laws that restrict what they can offer.
A spike in data consumption and ARPU
OK, there'd be mass industry seppuku if customers didn't use significantly more data, and the Koreans have well and truly ticked this box. According to SKT, a 5G user burns through an average of 33.7GB per month, 65% more than a 4G customer.
It's early days, but there's also been a slight uptick financially. SKT says in Q2 5G services boosted service revenues and led to a 0.4% sequential improvement in ARPU (average revenue per user). KT's ARPU rose 0.8% sequentially. While these are tiny steps, a trend may become more apparent this quarter. Of course, marketing and subsidy costs are another matter.
Good for Korea Inc
South Korea's aggressive rollout has been good for Samsung Networks in helping open the door for new contracts outside South Korea.
With an assist from the Huawei ban, it has just been named one of KDDI's main 5G vendors in Japan -- a major breakthrough.
Work in progress
Early network rollouts sometimes suffer from uneven performance, but an Opensignal survey in June found average 5G download speeds of 111.8 Mbit/s, or 48% faster than users with 4G flagship phones -- not a bad start.
The maximum speed observed was 988 Mbit/s, 8.8 times as fast as the average speeds. SKT says it is now witnessing download speeds of 1.5 Gbit/s to 1.8 Gbit/s.
As Opensignal says: "We expect the experience of 5G users to change during the course of 2019, as 5G's coverage improves and vendors resolve initial 5G problems."
This is the drag on latency as devices shift from LTE to 5G -- a big deal for early rollouts where users spend much more of their time on the legacy networks. IHS Markit RootMetrics found that on KT upswitching could move the latency needle from 88 to 244 milliseconds.
It is one of several problems that come with trying to integrate non-standalone and standalone networks. With the steep cost of deployment, it will be some time before operators are running mostly 5G standalone.
What didn't work
Wavve mobile TV
The new HD streaming service Wavve, a partnership between SKT and the three biggest broadcasters, is struggling to gain traction.
Partly it is because of technical issues -- users are complaining about buffering and poor image quality -- but also because of the limited access to and content.
The telco was ordered by the Fair Trade Commission to correct ads that claimed its 5G service delivered 1.7 Gbit/s when it was available only in 3.5% of basestations.
— Robert Clark, contributing editor, special to Light Reading