Well, haven´t test it really, but have read much about it.
Just now i´ve installed a rad with two entrances and 2 separated circuits inside. This helps water-flow to be slower through the rad and the dissipation better. The performance of this type of rads and the Evo one (have one installed too) is better.
Here at Spain several people always ask the same question, if rads connected in parallel would perform better as in serial. The answer of people that had tested the two ways of connection is always the same: Parallel.
Computer during mounting time:
Cheers,
friku.