That is a fabulous photo of the pair of them together, like huge Airfix models! Where is that location?
Back to your question of which was the more successful, Overall it has to be Concorde but the Tu-144 has several 'victories' it can point to.
The Tu-144 was the first SST to fly and it was the first to exceed mach 2.
It was also marginally faster (about 100mph) so Tupolev has the claim of first and fastest.
By coincidence the production run of both types ended after 16 aircraft so that ones a tie.
The fact that it was allowed to fly over the USSR isn't really a measure of success, large tracts of the USSR are uninhabited and its not really that
different from flying over the Atlantic as far as that goes, it certainly doesn't mean that the Tu-144 was quieter or anything.
In fact it was considerably less efficient than Concorde as it needed to keep its afterburners lit throughout the Supersonic flight regime whereas
Concorde could switch its burners off and maintain 'supercruise'.
The ultimate measure of success though must surely be the fact that the Tu-144 made 55 passenger flights in a 7 month period between Oct '77 and
June '78 and never carried passengers again, Concorde on the other hand operated supersonic passenger flights on a daily basis for 27 years,
beginning in Jan 1976, interrupted only by the tragic loss of the Air France Concorde that was hit by debris on the runway in 2001.



