Hi, you dont have to use sysprep to deply a template but if you are using a domain then when you try to join the new server you will get GUID errors and it will deny you memebership, one other method is to use NEWSID after the template has run and change it this way, no errors but is not a supported tool by microsft especially used this way.
to be honest what I usually do is create a saved config for the sysprep to use and when going through the wizard point it at this config, create once and use again and again only chnaging comuter name, you can have all the full benefits fo a unattended file simply in minutes. requires virtualcenter and to have the sysprp file i nthe folder on VC of course but only a one stop shop.
Positives if sysprep:
full new clean fresh GUID machine with no real relationship to the template,
only create answer file once and can be re-used at a click of a button.
fast to deploy
can re-use all domain/ authentication/ ip subnet information again and again (changing IP and name of course)
can create config file to only ask simple questions even though it is an answer file.
choose nerw name, IP address etc
takes a couple of minutes to ensure you have the right sysprep in the right place.
have to create an answer file (not really a neg as only takes 1 min)
Hope this helps