to everyone:

It seems that neither of those reviewers never used spotlight or just don't know how to use it

Reason #1 Smart Launching: Spotlight does the same thing. it can list your applications based on your behavior.
Reason #2 Control Your File Search. Spotlight cant do the same thing, even better using the kind trigger. Besides,it seems that Alfred doesn't find all my files , with a 40% fail rate. Spotlight find ALL my files.

Reason #3 Web Search: Spotlight can do web search too. Even have a web history search!

Reason #4 System Commands: Thats true. Spotlight can't do system commands.. THANK GOD!. I don't want to log out accidentally again while searching for a file called logs.sys. Stupid Alfred.

and about this review:http://www.macstories.net/mac/why-i-ditched-spotlight-for-alfred/. It seems that the guy switched to Alfred just because, without any valid reason. Spotlight slow? doesn't find his files? i think he missed up his own system

To END:http://www.macgasm.net/2011/02/08/theres-a-new-man-in-my-macs-life-and-his-name-is-alfred/
The only cool feature that this guy mention is that you can do custom searches. Yea , i missed that too, but then i found a more powerful, robust and versatile application for that: GlimmerBlocker.

GlimmerBloker is a ad blocking proxy that lives in your system. It doesn't only block ads, but it also let you to create custom searches , custom styles, modify web content... GLOBALLY, without missing up with your safari, spotlight or whatever because it never touch any applications, is just a proxy.

Right now i have tons of custom web searches that i can access from spotlight, the safaris' url bar, and even works in firefox, google chrome or what ever applications that connects to the internet. Alfred is a pitty compared to that.