Buffalo Ministation Air and Time Machine?

[Danneman101]

Just wondering if anybody here is using a Buffalo Ministation Air (with built in wifi etc) and can answer one question about it?

Is the Time Machine backup (done via wifi, not using the usb) in sparsebundle format (ie. the same as if it had been backed up to a nas), or is it in regular file format (ie. the same way as if it had been backed up to an external usb hard drive, for instance)?