Spot on....the lads who deployed on Herrick 8 with my lot also did pre-deployment in Kenya with us on the CALFEX, not sure what Artillery unit they were but had just come over from Germany with very little time to convert from AS90 to 105's. Poor *******!!!
But ammo takes up more space and is more expensive.
GMLRS provides greater accuracy which equates to less collateral damage than a battery of guns. I suspect it is also less manpower intensive to operate, but someone in the know will have to comment on that.