Small Business Server – Pro’s / Con’s

I’ve been working for a small company for 6 months. We use Small Business Server 4.0. I have been tasked to begin upgrading to SBS 4.5.

I’m under the impression that SBS is quirky (ie. we must reboot the main server twice a month because it bogs down). Obviously, I can’t find anything at Microsoft about 4.5 issues.

Can anyone provide real world pro’s / con’s about SBS 4.5? Also, if I don’t use SBS 4.5, how can I get the Win NT domain to recognize Windows 2000 users?

-MP