The "time spent" on generation argument doesn't matter if the generation of the content takes an (or some) order of magnitude more than the generation of the markup and if the resulting content is not cacheable.

A templating system (although called Perl Preprocessor) we have, are and will be using is Text:Vpp for dynamic document generation (mainly LaTeX files).

I have some advice:

From my experience as project manager: Don't get passionate about this (advocacy). You have found a nifty tool. But don't try to apply it to solve all (templating) problems you have. For some of them it is too big, for some it is too small. I didn't say it is useless. There's a big bunch of things where it is exactly the right thing.

From my experience as computer scientist: The expressive power of a given system is of course dependant on its - well - expressiveness. I mentioned the comparison between Perl, a *real* Templating system and HD. Of course everything is possible by extension. You may include even perl-code to a template to achieve some things, but then...

...From my experience as programmer: you really have messed up your design. What you planed to achieve - separation of code and data - for better maintainability,reusability etc. gets lost.

And finally from my experience as managing director of two companies whose core products are based on Perl:

I do this for a living too. :-)