MAME Split Merged and Non-Merged Sets

Some MAME Torrents are released in up to three different flavors:

Notes:
 * All MAME torrents available on Pleasuredome were created in a way that their contents can be used directly in MAME or Frontends, without the need of copying, moving, renaming, compressing, or extracting any files or folders.
 * No setting is needed to tell MAME which set type is being used. MAME always looks for files in all expected possible places.

Comparison Tables
For illustrative purposes, below is a comparison table for the "MAME ROMs" torrents:

A comparison table for the "MAME Software List ROMs" torrents follows:

Conclusion
In short, the three set types have the same contents, but organized differently. In fact, if you have one of these torrents, the other one(s) can be created using a ROM Manager such as clrmamepro or RomVault because the contents are the same.

Note that Non-Merged is about two times larger than Split or Merged, which makes it a bad choice if the intention is to download the entire torrent (any of the smaller torrents can be downloaded to create the Non-Merged one).