I may be wrong here, but with my limited FCP experience, my xdcam-hd files had to be rendered into my fcp project as well, apple just didn't use the sony transfer utility. As far as length of imports go, I imported 32min 1080 / 23.98 footage in about 10 minutes. The speed may be affected by your cpu, I'm not sure about that. I'm on a 8 core 3.2ghz mac pro.
We have a PDW-1500 connected to the Media 100 via firewire and mounted on the OSX desktop.
The files on the XDCAM are MXF-IMX-50 SD 16:9 media files.
Media 100 does not support IMX so transcodes the files to chosen media format. The files are standard definition and widescreen.
After import the files in the media 100 bin are 4:3 aspect ratio.
That means when dumping them into the timeline, media 100 asks to conform media or interpret as 16:9