Is there any advantage/downfalls between using the inline write tag instead of the resource tag? Example:
<%=Resources.Site.SampleString %>
These methods will function exactly the same. The latter simply calls first one; there is a reason why strongly-typed resources access code is being generated in the background. Therefore you can use whatever method you please.
By the way, there is also another way - by using meta:resourcekey attribute. So you should be able to write:
<asp:Literal id="Literal1" runat="server"
meta:resourcekey="SampleString" text="Default one" />
and it all should work exactly the same.
EDIT on implicit Localization.
What I forgot to mention, is that with meta:resourcekey certain conditions have to be met. The conditions are:
I realised after some time that the <%=Resources.Site.SampleString %>
method does not have designer support (which is understandable). This doesn't bother me, but it is a difference (for future readers).
So if you need or want designer support, the second option would be necessary.