I am not looking to start a raging battle. I think the OEM hitch looks heavy duty as hell and I am sure it is a better part.
I chose to go with this hitch:
2000 2006 BMW x5 x 5 Trailer Hitch Receiver Class III Reese Pro Series 51093 | eBay
$115 Delivered to your door.
Fairly simple install. You use the existing bumper bolts, and you drill a 1/2 hole into the subframe.
Rated for 6000 lbs / 600 lbs tongue weight which is all the x5 is rated for anyways.
Personally I think it is good ENOUGH. and in that degree it is great. I would never tow crazy amounts with my x5, because i love her, so to me the OEM hitch is overkill, especially if only rated the same.
Now I am not saying all of this without backup.
What I use my hitch for is hauling my dirtbike, not heavy, but quite significant tongue force. Bike weights 240lbs, it also held me and 2 other buddies jumping up and down on it. No signs of stress.
Please dont say its bending, the hauler doesnt fit 100% tight which gives it that slight angle. I have hauled like this over 20x without issue.
Just throwing that out there!