I have a 1 second difference between logo and login. During that time period, Vista is preparing network connections and launching pre-login services. Look in your startup services and apps for things you don't need (the larger the number of services, the greater the pre-fetch lag) and then test your network link speeds and routes. Chances are very good that you have a single network-sensing app set up for Everyone waiting for launch that Vista is waiting on that is causing the delay.
Vista won't let you damage the bootfile with disabling services - it just may be that some apps don't run correctly. I would suggest google searching "Vista services to disable". There are many websites that give you complete descriptions of the 39-40 new services in Vista with recommendations on which to disable for what tasks you perform with your PC. Sites like Tweakvista.com also have some suggestions and apps that can help you figure out how to increase your Vista performance.