u know the 2 put out almost the same power. the svt isnt really fast stock, i drove my friends for a week (yellow 04 euro svt). it moves good for stock, but not impressive. But i was coming from driving a modified turbo car to the svtf..lol so taht might have played a big part. but the car has alot of aftermarket ALOT! the svt 2.0 is a very very stout motor, awhole lot better thant the regular 2.0 zetec. Its a completly rebuilt version by cosowrth and svt. its a very boost friendly motor as well.
good info on the svt motor!
http://myfordfocus.com/svt/
if u do get one make sure id choose the euro version.. nicer wheels/hid's/
BUT!! if i had to choose id probrably go with the vdub.. but i got a fear of them, i hear too many bad stories of them and their repairs!
im willing to bet they oth are about the same speed wise..