Ok, just read the paper. They tested 3 services in 2013 with the following results:
1. "Although our input has been used by the service, it is not possible to find any direct connections between the input and output transactions"
2. "The service Bitcoin Fog bundles a large number of small transactions into a small number of large transactions, which are then used to create all outgoing transactions. The input transactions, however, remain untouched for a long time. This way, the service prevents us from detecting any direct connections between the input and output transaction in the transaction graph "
3. "In the first experiment, we were able to find a connection between one output and our input. Although the︀ direct link makes up only a small part of the transaction size, it is evidence︁ for imperfect anonymization. The second experiment did not reveal any connections."
I am not︂ saying using a mixer provides 100% protection from everything, but based on this paper I︃ definitely wouldn't say its a "bad idea" to use a mixer, or "it is easy︄ to follow" a transaction when a mixer (with a decent mixing algorithm) was used. Switching︅ to another cryptocurrency can also work of course, but sometimes it could cost more at︆ the end.