Mac OS X Server Vs Windows Server

[DJACID]

This question is actually from my mate,
he has finally saved up enough to get a 2nd hand server,
the computers he currently uses are -
macbook and dell laptop
at home a imac G5 and a dell 420,

he needs the server for different tasks and both Windows and OS x are perfect for the job,

as i always have been using a windows server i couldnt answer this as i have never used a OS X Server...

So if anyone here has used a Apple Server???
or if anyone has moved from Windows Server to Apple or vice versa???
how does it compare to each other???
how is the compatibility of a Apple server compared to Windows???

Cheers

[DJACID]

no worries sorted