@WovenTales Nice template but I think I see one small problem as you've written it. The single letter directory is the first character of the %albumartist% tag when I think it should be the first letter of the %albumartistsort% tag.
One thing that I use here that @nullbyte might want to add is $if($gt(%totaldiscs%,1),%discnumber%-,) just before the track number if statement. This will put in the disc number if it's part of a multi-disc album.
Another thing that I do here is put the artist information in the track filename if it is different from the album artist, by replacing %title% with %title%$if($ne(%musicbrainz_artistid%,%musicbrainz_albumartistid%), [%artist%],). Note that I use the %musicbrainz_artistid% and the %musicbrainz_albumartistid% tags for the comparison, to avoid issues with differences such as "Pretenders" versus "The Pretenders" (which both have the same ID). This works well for collections where the album artist is "Various Artists". The results look like:
Volume in drive X is Media Library
Volume Serial Number is B771-1318
Directory of X:\Music\Various Artists\Oh What a Feeling 3
2017-04-11 12:34 <DIR> .
2017-04-11 12:35 <DIR> ..
2017-04-11 12:02 2,857,780 1-01 Closer to the Heart [Rush].mp3
2017-04-11 12:02 3,462,834 1-02 Hey You [Bachman-Turner Overdrive].mp3
2017-04-11 12:02 2,095,094 1-03 Dreamboat Annie [Heart].mp3
2017-04-11 12:02 3,375,734 1-04 Sweet City Woman [Stampeders].mp3
2017-04-11 12:03 3,416,264 4-15 Bells [The Rankin Family].mp3
2017-04-11 12:03 3,401,586 4-16 Jimmy's Got a Girlfriend [The Wilkinsons].mp3
2017-04-11 12:03 3,564,251 4-17 Fall at Your Feet [Jesse Cook].mp3
2017-04-11 12:03 3,132,732 4-18 Consequence Free [Great Big Sea].mp3
2015-12-13 17:15 62,339 cover.jpg
73 File(s) 273,103,158 bytes
2 Dir(s) 5,047,198,019,584 bytes free
Then again, it's all about personal preference. That's the beauty of using the scripting in the Picard formatting template. Everybody can customize it to do pretty much whatever they like.