I drove a welded diff on my first ohc-turbo as an everyday car, and except from parking and tight turns it really isn't noticable. A bit more noise at motorway cruising tho.

BUT, when I drove it in the wintertime, it understeered massivly. Always had to tap the throttle to get the back out in turns, or else I would've ended up in a ditch

But you have to love the predictability when playing around

http://www.youtube.com/watch?v=rqgXsNdGWLM