I'm not done reading the paper, but I suspect that astoria clients could be distinguished from regular tor clients at least by the fact that they do not pre-bui

I'm not done reading the paper, but I suspect that astoria clients could be distinguished from regular tor clients at least by the fact that they do not pre-build circuits. This means that the anonymity set has been partitioned, especially given that the authors say "From our evaluation of Astoria, it is clear that the performance-security trade-off is favorable only in its higher security configurations." So there is a danger that people who perceive themselves to need higher security and use this client will lose anonymity guarantees as they are mixing with a much smaller group of people who all consider themselves "interesting targets". The big reason tor is so effective is because they've performed a lot of outreach and gotten different groups to use it, resulting in a large and heterogenous set of users. Of course, this is still very interesting research, and maybe it will be integrated into the official tor client. I know there have been many discussions of AS-path-based selection in the past.