What's really in all those .MTS metadata files?

[VanillaMozilla]

Is there really anything worthwhile saving in the AVCHD (H.264) file structure besides the videos?  I can rewrap a huge video in seconds without transcoding, with
avconv -i file.MTS -c copy file.mp4
Avidemux 2.6.8 seems to handle them just fine.

The directory structure seems like an awful mess, in that it gets in the way of renaming them and moving them where you want them.  There are alternatives that promise to extract the video and metadata "properly", and everyone promises a disaster if it's not done properly.  I don't want to get into another mess like I did with .VOB files.  On the other hand, so far I haven't actually had a disaster.  Does anyone REALLY know what's in all those other files?  Can I safely dispense with them?

[mean]

the TS format is originally meant for streaming
The side informations contains seek points, info, etc...
If you convert to a format with seek capability (all except TS basically), you are good