Thanks Lee and Tom.
Lee, that behavior (still allowing access to the .adp or the .tcl when the template is what you really want to serve) has concerned me for a while too. Rather than default to a separate directory, wouldn't it be better if the RP for example did the following:
User requests http://somehost/page.adp
rp checks to see if both page.tcl and page.adp are present
if true, redirects to /page