How much stress creates pathauto in Druapl 7?

There is a desire to make the blogging site structure on the drupal 7 version. Initially, the simplest functional , but ...
In Drupal 7 have the option to create a human readable URLs and use the token, pathauto, transleation I can do URLs type : recept-borwa.html addition to the " mythical " use of url to search engines , to me , in this case it will be easier to escape to samopis (html + include) at high traffic blog. Forgotten the name , but in Drupal to be connected to the module which redirects to duplicate pages ( to a page node/31 me redrektilo on recept-borwa.html).
These modules do so many requests for a sample listing. Although the true drupalery assure that such requests are simple and light weight as a server, but I 'm not sure. Let's say on my blog from 10,000 up to 100,000 pages.
Suggest options : What type of URLs to choose Drupal
1. Leave the " dirty links " ( fastest)
2 . Leave the " dirty links " + module in apache config include (very fast , probably)

RewriteEngine on
RewriteBase /
RewriteCond% {REQUEST_FILENAME}!-F
RewriteCond% {REQUEST_FILENAME}!-D
RewriteRule ^ (. *) $ Index.php? Q = $ 1 [L, QSA]

3 . Enable clean URLs node/35 ( very fast , probably)
4 . Include the above modules and get the beauty of recept-borwa.html ( slowest)
ps
Site optimized for advance a large attendance .