I just visited IGN's PS2 page, and this is what they had to say about their recently acquired copy of N. American Fifa 2001 MLS:

"Well, it's all good news for U.S. soccer fans as the game is shaping up very nicely...

...today we're pleased to say that the slowdown problem has also been nixed as the current version of the title features no slowdown whatsoever."

But most importantly, check this out:

"The game now has a shot power meter that works a lot like it does in Konami's soccer titles. While we haven't really played enough of the game to tell if this addition significantly enhances the gameplay or not, but it's definitely a plus and not a minus."

For more info, go here: http://ps2.ign.com/previews/14401.html