Ubuntu Stock Firefox is sllloooww

[Gabriel Dragffy]

Just installed FF2 on my Dapper system, following some instructions in
the Wiki. It even says in there that the Mozilla build of FF is
significantly faster. I didn't really believe it and thought I wouldn't
notice anything anyway.
But it really is faster - it seems to scrape the hard drive much less
when loading it up and pages are displayed instantly.
I do remember this being covered quite some time back, but at the time I
don't remember any over-whelming reason given.

Why is the ubuntu build so much slower? I can't understand it.