I would agree with Dion Hinchciffe in his article "SharePoint and Enterprise 2.0: the good the bad and the ugly", and am inclined to agree with some points he made about the downsides of SP - cost and complexity, not web 2.0 native, self service not emphasized. Although its marketed as mainly a SMB tools, its really not ideal for small firms, especially the sub 100 segment. Light weight web native solutions like HyperOffice are more suitable for this context.