Booked my D2 into Simmonites for some work including a 2" lift, they are recommending that I ditch the rear air springs and replace with coils. The reasoning being better off-road articulation and increased longevity and reliability. I do trust their advice as they know their stuff but am not sure if I should screw up the car too much from OE spec (they are planning to remove the compressor, pipes etc.)

Has anyone done it this way? I was originally planning to fit spacers and retain the air springs.

yeah it can be done quite easily, you'll need to re-configure the SLABS ECU and tell it it's got coil suspension otherwise all yer suspension warning lights will be on.

Any dealer can do this