Picard is amazingly powerful and I've used it for many years to manage my Music directory. I've done many tweaks to my file naming script over the years and I'm sure I'm not done. My current one looks like this:

  $if2(%albumartist%,%artist%)/%album% 
  $if(%originaldate%,\($left(%originaldate%,4)\))/
  $if($gt(%totaldiscs%,1),Disc %discnumber%
  $if(%discsubtitle%,: %discsubtitle%,)/,)
  $num(%tracknumber%,$if($lt(%totaltracks%,10),1,$if($lt(%totaltracks%,100),2,3)))
  %title%

I have "Replace non-ASCII characters" and "Windows compatibility" both unchecked. At present I'm kind of 50/50 on single-digit track numbers for albums that have less than 10 tracks, kind of just used to everything being two digits (though I have a handful with greater than 99 tracks, so there's the concession there for triple-digit track numbers).

It's also very much optimized for my own use of the file system being my library management. I just change directory and play. ;)