Drove three sets of BFG MT (235 x 85) to more than 85k km - 2 sets on my old defenders and one set on my 280G. I was very impressed and probably would have fitted another set on my 280 if i was not misled by a tyre dealer in PTA (my old bfg gave up the ghost as i was on my way through from Bots and had to order en-route and have it fitted urgently that he is selling me BFG's but turned out to be KUMHO MT's- the guy promised me and Andrew that the tyres are BFG' - (i could not find BFG's then and had to take the Kumho's, fortunately at a reduced price)
Now the Kumho are not the same imho - i do not think they will make 60k km
I bought my 290 with BFG AT (31 x 10.5)- and had the same chipping problem. I changed them with 30 x 9.5 michellin ATX - and i was impressed. I recently changed them after 105k km and probably would have been able to squeeze another 5 out of them. Luckily did not have a single puncture or a flat on them.
I fitted 31 x 10.5 Michellin ATX squared about 15k km ago, and this far this good..
So my verdict - for rough terrain and obviously mud 235 x 85 BFG MT - they also work fine in the sand ( I am not sure but i am sure these are the tyres used by most DAKAR racers)
for all other work - Michellin ATX..