16 bit little endian or 24 bit?

Background:

I've owned a Panasonic TM700 for several years now. In the past I have always used iMovie but several months ago started using FCPX. I have been using ClipWrap to rewrap the files because FCPX doesn't recognize video clips from my camera when connected. However, I just recently discovered that if I insert a SD card into the slot in the camera, copy the files to the card (note that I said "copy" not "convert"...nothing is happening here other than copying the files from the camera's internal flash storage to the SD card...only takes a few seconds), then insert that SD card into my Mac, FCPX will recognize and import the video clips as if I had connected a compatible camera. It's really weird why it will recognize the clips on the SD card when inserted, but will not recognize the same clips on the camera's flash memory OR the same SD card when it's in the camera (and the camera is connected by USB). Very weird. Anyway...

My question:

There are several differences between files imported directly from the SD card and those that are rewrapped using ClipWrap.

One is that the audio in the files converted directly by FCPX from the SD card is 16 bit little endian, whereas the ClipWrapped files are 24 bit. What's the difference, and does it matter?

File sizes are also different: ClipWrap files are slightly larger.

Bit rates are different also: once again, ClipWrap files have a higher data rate (30 as opposed to 27).

Also, processing the files is MUCH faster using the SD card. ClipWrap takes a long time to process the files, and then FCPX has to process them again on import. So if I could just use the SD card method, import times would be greatly reduced.

Thanks in advance for your help.