WinServer 2008 R2 Pros and Cons?

Hey my company is considering switching from Unix to Windows Server 2008 R2, for RAS reasons. We need a reliable server that can grow, hopefully substantially, in the next couple of years as business expands. I have read some docs recently that Windows Server 2008 is reliable, is this true? Currently we run Linux what are the benefits of switching to WS2008 over sticking with Linux?