Any known issues with img (11.2.4MU1) and 'hybrid' drives?

We've had some 'high performance' (!?! ;-) laptops arrive and been asked to prepare them for our environment
They are Dell E6540 with Seagate st500lmo 00-1ej1622 drives.
The 4GB base image is taking 50+ minutes to lay down... takes about 9mins on standard SATA drives...

We've not started any digging yet, but thought I'd post to see if anyone has seen this type of behaviour?