it's been amost 10 years since my last TanTan frame build, but I see that they have not changed. The recommendation is the same as 10 years ago: do not buy from them.

I assume that reading threads like this biases you a lot. Those people who don't have any issues with their frames don't post here.

I have finished my build this week and so far I am very impressed. The carbon quality seems to be very good.
The assembly process was quite hard for me, because I have never asseembled a whole bike before and I had to face some issues. For example the output holes for the brake hoses in the handlebar were too small. So I made them bigger with my girlfriend's electric nail file 
And I had a few minor problems with the expander and this crazy centering ring because of my own silliness.
But after a few days I made it and this the result: