As far as I am aware you are correct that Goodyear have stopped the original MT/R but are to replace it with a new improved version.
As far as on road performance using the original MT/R tyres goes - they are an off road biased tyre - drive accordingly!! they will not grip a wet / dry tarmac road like a road tyre.
Saying that I have not had a problem on or off road with these tyres apart from on wet slick road surface but then that can happen with a road tyre but is more predictable.
Off road they are not as good as a BFG Mud Terrain as the tread blocks are much more open on the BFG. I would say the MT/r are more akin to the old BFG Tracedge in road and off road performance.
They resist punctures well and with the strong sidewallls can take a fair beating. Ideal for wider section wheels as fitted on RR, D3 etc where pinch flats are common.
In 235/85 x 16 size
BFG MT KM2 has a 'Q' (99mph) speed rating and a '119' (1360Kg) load rating
The Goodyear Mt/r has a 'P' (93mph) Speed and '116' (1250Kg) load rating.
The G90 (7.50 x 16) has a 'N' (87mph) Speed and '116' (1250Kg) load rating.
BT08BTX (Beatrice)
Atlantic Rising 110
The 130 also needs to be run on steel wheels too due to load rating. The Boost alloys as fitted to 110's are not high enough load capacity to meet that of the 130.
This is why LR fitted them to the 130's.
Will have a look at the load rating of both to see if there is a major differance and go from there.
neil 2003 Defender 110
Stage 2 Comms G4SAF17 Fleet no.160
Past Vehicles
2008 Defender 130 (BD08 VTK)
2003 Discovery 2 Surpport vehicle (BT52 OWD)