I can understand why though as the limited storage capacity is quite a deterrent for most (but not all) to have hires files kept in their iPads. In fact, even for myself, after the test I've pretty much set iTunes to downsample all my music to 256kbps AAC when syncing to the iPad and iPhone (but not touch the original on the iMac itself). iOS doesn't seem to like full filesystems. So I've wiped out my hires off my iDevices. I'd rather have my hires files on sonically more capable device like the iBasso DX100 and keep my iDevices as a big jukebox.
This thread, at least reading based on the OP's first post is more collating a bunch of (USB->CCK?) DACs that work with the iPad.