The "package-info.java" file of o.a.c.m.random does not mention the problem of seeding.
Many users of CM could not be aware that it is not sufficient to "randomly" choose a seed in order to ensure a random sequence.
I think that this is what is illustrated by random failures of some unit tests (when the seed is "randomly" selected).
Do the intricate initialization procedures provided in some implementations (WELL family and ISAAC) ensure that all seeds are good enough?
Should we provide some tool to test a seed?
By the way, the WELL performances listed on this table do not correspond to the results obtained on my machine with our PerfTestUtils benchmark: the MersenneTwister is invariably faster than all WELL implementations.
Update: the two benchmarks actually agree that MersenneTwister is faster than WELL.