bmw superceeded XO with XJ for all LSDs, and IIRC, most dealers use XJ as their sole fluid.
I'd run amsoil severe gear... the 110 wt is probably a good bet, given that BMW diffs tend to get whiney.
The diff (car) and final drive call for 75w-90(xo) and neither have LSD's. I myself don't know of any BMW cars with LSD's though many BMW enthusiasts lament the fact that their cars don't have LSD's...especially these days as power is getting significantly higher across the product line. Maybe the X3/5's come with LSD's?
Many on BMW motorcycle sites say any GL5 75w-90 at reasonable intervals will do - SAF-XO is not necessary with this maintenance philosphy. The thought is that for those who believe in lifetime final drive fluids should use the more expensive SAF-XO.
That's not me, I've done the car once at 30k miles with Redline 75w-90. Will likely stay with every 25-30k miles. The bike calls for a change at 600 miles then never again. I'll do it at 600 then every 2 years thereafter (likely every 8k miles - the bike only needs 0.21L)