The out-of-the-box scale-dependent room tag tools, provided in the Documentation Tool Catalog - Imperial and - Metric, use the new tag tools, just like their single-scale bretheren. Unfortunately, there is no way in the tag tool to specify a scaling type - all tags using the tag tool have annotation scaling applied. For single-scale tags, that would be my preference, but the scale-dependent tags are designed to be inserted at scale factor of 1; the view blocks inside are already pre-scaled for three differenent scales: 1/16" = 1'-0", 1/8" = 1'-0" and 1/4" = 1'-0" for the imperial tag and 1:200, 1:100 and 1:50 for the metric tag. Applying annotation scaling to these tags causes them to be inserted incorrectly under most drawing scale/annotation plot size combinations, including those likely to be used.
I can think of two work-arounds, neither totally ideal, but if scale-dependent tags are important to your workflow, you may need to decide which is the better way to work for you.
Keeping the Out-of-the-box Content and Tool
You can get the out-of-the-box tool to insert the tag at the necessary scale factor of one by setting your drawing scale to be the inverse of your annotation plot size, while placing tags. For example, if you are in an imperial drawing and have 3/32" as your annotation plot size, you can set your scale to a custom scale of 32/3 [10.666666666666666...]. Do this by calling up the Drawing Setup dialog, selecting the Scale tab and choosing Other... from the Scale list. This makes the Custom Scales edit box active - type 32/3 in the edit box and select OK to return to the drawing. Place your scale-dependent tags, then remember to reset the scale to an appropriate value for any subsequent editing. You can also set your annotation plot size to the inverse of your drawing scale. So if your drawing scale is 1/8" = 1'-0", set your annotation plot size to 1/96. Working out the inverses is, of course, much easier for metric users.
Creating an AEC Content File and Tool
The other option is to set up an AEC Content file using the Create AEC Content Wizard and the _AecAnnoScheduleTagAdd custom command, just like all tags were done in previous versions of ADT. On the "second" page of the Wizard, you will want to choose the None radio button under additional scaling [and set the X, Y and Z scale factors to 1, unless your Multi-View Block requires some other scaling factors to work properly]. As in prior versions, you will need to put your finished AEC Content file somewhere under the root folder specified for AEC DesignCenter Content on the AEC Content tab of the Options dialog. You will also need to create a file to hold the Property Set Definitions required by your tag, place that file in the same folder as the tag or one folder above the tag and specify that file as the source file in the _AecAnnoScheduleTagAdd command string. In previous versions, this source file was called PropertySetDefs.dwg, but you can call the file by any name you like, as long as you get the name right in the command string. This is my preferred method of handling scale-dependent tags, but I am bothered by the need to have Property Set Definitions defined in two places - the source file for all of the other tags and the "PropertySetDefs.dwg" needed for the scale-dependent tags.
You can read more about scale-dependent tags here.
Here is hoping that a future version of ADT will allow the user to specify a scaling type in the tool, so that all tags can be kept in the same source file.
1/20/2007 Update: See this post for a way to set up scale-dependent tags without setting special combinations of drawing scale/annotation plot size, needing two source files for Property Set Definitions or "breaking" existing tools by moving the out-of-the-box scheduling source file.