Speed issues,
IMHO, I prefer useing a totaly database driven template system, I find it to be stable, And fast enough to do what I need it to do, As for the sdtability questions. I think both would be equal, provided you are useing stable code.
If you were to do some speed tests you could find that they are the same speed. If they are not. Have a look at how you are "reading" the template.
My 2 cents worth.
Tommy