The worth on using it is directly proportional with what you would be using it for.
If you only intend to display static pages, than yes, Smarty is useless. If we're talking about dynamic content however, than Smarty has a lot to offer... it is not just a tempalting engine, but it has a lot of functions to also process the template variables before parsing (like making e-mail addresses invisible for SPAM bots, or displaying a number in money format, or a lot more....) or even process the whole templatge before displaying (like the one for trimming out spaces... and guess what's that good for...? it narrows down the necessary bandwidth for the site... and helps the pages load faster).
This is Smarty, in a few words.
Just check out the website, the WiKi & FAQ & the documentation are *very* good!
Touche criserb.... but, what I was looking for now was a little more advanced personal experience... like if from a performance point of view is Smarty the best choice knowing that it uses a caching system that converts the templates back into PHP code... I'm a little concerned about that and am thinking that even though Smarty adds a lot of excellent features, maybe it does that by taking out a little performance.... anyway I was just curious if anybody could enlighten me on this... and my answers on other threads could hardly do that....