1. Basically yes, but there are other sets as well (the bootleg, boss hacks, final?, fatalities enabled etc.) For the record, my decrypted set is the bootleg set that first came out. After getting the sound fixed and eventually unlocking the fatalities, it works just like the original set, sans the encryption. 2. The is no such thing as "the best" set if you ask me. If you are like James, you might think about the encrypted original set as the best, since it's exactly the same as in the arcade (by this I mean the presence of encryption on both). 3. Again, there is no such thing as "the best" DAT. The DAT only describes a set. Whether a DAT is "the best" DAT depends on what you think can be considered the best. If the DAT makes the set work without errors or bugs, wouldn't you consider that "the best" DAT, as you put it? 4. Check the end of this page for possible DATs. 5. The fatalities are not hacks. The developers just locked them out for stupid reasons. 6. I think the encrypted set has the fatalities unlocked by default (don't take my word for it as I have the decrypted set with fatalities enabled by a P1 hack), but if they are not or you'll have a slightly different set (the decrypted one for example), you can either: Use the Universe BIOS to unlock them, use a code to unlock them (search the board) or find a decrypted P1 rom that automatically unlocks them. 7. You should be able to, just check this topic for a few needed stuff (GfxKey, PCM2 and GfxCrypt values) if you have the encrypted set. My decrypted set works fine, although the P1 rom has undergone a few changes to accommodate some of the bootleg set's shortcomings - locked fatalities anyone? 8. There have been reports of games not working or having other problems if you use "Neo" or "neo" instead of "NEO". Always use NEO just in case.