In my opinion, the advantage of implicit localization over explicit localization is that if you have several properties for localization for a given control, this is a more economical syntax.
In the case where you just need to localize some text, I use the asp: Localize control, which has only one property (Text), which is displayed in the user interface. Is there a reason to use one over the other? Any style of preference? Are there any differences in speed?
Implicit
<asp:Localize ID="Localize1" runat="server" meta:resourcekey="Something" />
against
Explicit
<asp:Localize ID="Localize1" runat="server" Text="<%$ Resources:Something %>" />
User
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