Wget seems to spend more time for downloading packages...

I guess that the only chance for pacman to download faster it to use multiple identites or some trick. That mean cheating.

Wget is known and recognised app from UNIX that use GPL licence. For PACMAN i dont know because wikipedia gives me the game page instead. (it has some name issue with popular game)

see?

pacman uses libfetch. I just use pacman's libfetch because the output is nicer. I think some people claim that wget (or curl) can be faster. The real benefit is if you want to customize the download command. (Also, for a while there was a bug with libfetch that failed to close connections and after downloading a few packages, the new connections would be refused - but this has been resolved recently).

There's also a wrapper for pacman called powerpill which downloads files concurrently. I've always been happy with straight up pacman.