So all-in-all I cannot use this distribution as I was saying earlier - limited
In my opinion I don't see it doing what Windows can.
Without getting into a religious war here, of course SME doesn't do what Windows Server does. It has its own sharply defined set of competencies that it performs magnificently but it isn't "all things to all people."
You wanted to set up a public DNS server? Well, SME doesn't do that out of the box. Did you understand the distinctions among server-only, server-gateway and private server-gateway? From your posts about the "second NIC" in your SME box behind a router/firewall, I think not.
Personally, with the advent of shadow copies in Server 2003 I've stopped using SME for fileserving for the most part ... but for small organizations with little or no budget for Windows Server, and for home use -- and for plain ease of setup and administration -- SME can't be beaten.
It's all a question of the right tool for the job at hand.