I've drive the same car with 7 welded diff's in !! Lot's of people on here have been out in my car wit the welded in & as Stav/Chip say slow speeds you do feel the tyres scrubbin, but thats to be expected your'll also hear any play you have in the CWP, shafts, prop, diff mounts etc as the car scrubs.

As for the steerin, I can't really comment, I've not got PAS on mine & when parkin etc it's as heavy as fook anyways !! Didn't notice any major difference when fitted the welder in over the plated & standard items I had before !!

jb