Summary: Summing up the results of tests, we can state with confidence
that Pentium 4 641 (Cedar Mill) has indeed proved successful. But its
"hobby-horse" is not in the performance but the superb overclocking
If you intend to use the processor in the nominal mode, then
the most promising choice for you would be to buy its dual-core brother
which is priced 25$ higher.
If you plan overclocking, the situation is changing.