PDO Vs MySQLi Vs SQL Queries.

Hey Guys,

I came across this article.

http://net.tutsplus.com/tutorials/php/pdo-vs-mysqli-which-should-you-use/

Though I've been working with PHP for over 2 yrs, i never bothered to use
the techniques mentioned in the articles like this.
What i do for DB connections and queries..is just simple sql queries in php,
$sql="{sql query}";
$runsql=mysql_query($sql);

What i do take care is to clean the user inputs before querying the DB.

Is this a good way? Coz i've seen more experienced programmers using the
techniques mentioned in the article, with PDOs, MySQLi etc...

I always thought there is a chance that these might slow the querying
process?

Please advice.

Any help is appreciated.

Thanks,
Vinay Kannan.