The Sandra synthetic scores certainly do not flatter the Athlon XP. The Pentium 4's Ghz advantage is just too much for the Athlon, and it loses by about 20% at stock speeds to the P4. The Pentium 4 is also the clear winner in memory bandwith. The nForce2 Ultra400 and 400mhz FSB is enough to propel the 3200+ past slower Athlons, but it is no match for the 875P.
In real world gaming tests the difference between the Athlon and Pentium 4 were much smaller than the Sandra tests. Freelancer was a very close race, with the Athlon only behind by about 3%. UT2003 favored the P4 a bit more, by around 9%.