Regarding the (new) gui I am still disappointed by:
Any client with a recent protocol stack tries IPv6 first. Here at ripe atlas the clocks go backwards. 
Hi again and thanks for the feedback. Unfortunately, it is still more likely that probes are running v4 than v6, which is why we made those the defaults. However, I just created a new preference that you can check out on our beta site at:
In the General card, you will now see a dropdown that allows you to select your preferred address family, and then when you visit any of the items you mentioned, you should see them default to v6 (if they are capable, otherwise they should show v4 information).
Please give it a try and let us know what you think. There is still some development and testing left to do on this but if all goes well we can roll this feature out to production in short order.
Kind regards,
Stephen
Atlas UI
Thank you for custom configurable solution via preferences. In my first try it works perfectly.
One word to your argument “it is still more likely that probes are running v4 than v6”.
Unfortunately it seems to be true. Nevertheless some statistics say users perspective is nearly 50/50 (google: ~45/55, Facebook: ~41/59, cloudflare ~40/60, apnic ~40/60)
Also probes do not reflect, that many users use mobile networks. But that is a different story ( I try to solve that problem a little bit with my probes.)