The new Xserves may seem like a good deal (we have a bunch of the old G5 ones), but not everyone thinks so: Paul Murphy posits that they’re much more expensive than Dells, for example. But in Paul’s comparison, the 16GB RAM configuration plays a key role: He chose the 4x4GB FB-DIMM configuration that is a whopping $6000 more than 8x2GB for the Xserve.
I suggest you to take anything from Paul Murphy with a grain of salt. He has a history of articles where the common denominator is his dislike of x86, love of RISC (both PPC and SPARC) and he seems to have lots of issues with Apple's decision to go Intel.
Even a few days ago he suggested that PA Semi, Freescale(!) and even SPARC would have been better choices. But given the processors PA Semi and Freescale are shipping at the moment, the wonderful selection of notebook SPARC parts and Apple's obvious success with Intel transition I don't share his views.