From the ones i've poked my nose under and had a quick look at, i'd say the wolf XD bars are about the same thickness as the scrapiron "HD" ones... they're certainly much thicker than the standard factory items.
However.... i used to have a scorpion rear bar on my 110... as good as it was for keeping the thing upright in bends, it really hampered axle travel, and when i went laning in it, i managed to shear one of the bolts off (that goes through the rubber bushes on the link) as it was that stiff (and my 110 has 130" dual rear springs, so quite a lot of force there)
In short... unless you're carrying really heavy loads mainly on road or just "tracks" as opposed to proper off road use with axle twisters, i'd stick with a standard one. i've now got a standard one on the back of the 110 and it handles nicely and i still have axle movement.
* the chap down the road from me does tree surgery... he's got a 110 tipper, and has huge rear springs and a huge A/R bar... it's painted orange, so i suspect it's a scrapiron type. he carries a lot of weight, but only across fields etc.
