The Pace Sky+ units (both versions) are installed with a 40GB Maxtor Hard Disk, spinning at 5400rpm. The majority of Pace Sky+ upgraders have therefore used Maxtor HDs running at 5400rpm with capacities of 80GB, 120GB, and more recently 160GB and 250GB.
300GB Maxtor 5400rpm drives have been tested but do NOT work on any boxes tested so far, unless their capacity is limited using the Maxtor tools to around 270GB. This seems to be a fundamental limit of the Sky+ software.
Amstrad boxes on the other hand seem to come installed with a 40GB Samsung SpinPoint Hard Disk. Therefore owners of these boxes tend to chose to use Sansung SpinPoint drives, usually with a capacity of 160GB.
The general consensus is that the ideal HD to go for runs at 5400rpm, cache shouldn’t be a concern. The majority of successful upgrades have been done with primarily Maxtor drives but also Samsung and IBM work well.
The drives which people seem to be using at the moment are:
250GB Drive: Maxtor 5A250J0
300GB Drive: Maxtor 5A300J0
160gb Drive: Maxtor 4R160L0, Samsung SP1604N
For reference, standard HD fitted in a Sky+ V2 is a Maxtor 2F040L0