Personally I liked Holmes Basic better but there are a few things I'd use, like some of the attribute bonuses for things like Strength for Damage.  IRRC Holmes had Dexterity modifying AC and missile attacks and Constitution modifiying hit points but not much else.  I used the +1 per point over 15 from Gamma World in the first version of Dark Passages.  But went to something that mapped more closely to fifth edition for the second version.  Class creation is based on the concept from the 2e DMG but some of the classes came out a bit wonky.  I keep meaning to revisit it.

Oh well, B/X is tight and simple as others have noted.  Being restrictive isn't a downside for new players and GMs.  Too many options leads to decision paralysis.  That's why random encounter tables and structured dungeon modules are good for introductory games.  But it was also TSR's most successful product and for many people it was THE D&D.

For us it's the combination of nostalgia (several of us started with Moldvay/Cook in the early 80s) and speed of play.  Without all the feats, extra rules, combat options, etc., we find that you can get far more actual playing done at the table.  For older people with limited gaming time, that pretty much trumps everything else.  None of us want to learn new systems & mechanics at this point.  B/X is simple enough to teach newbies and they've got it in a couple sessions.

As for some particulars, I like race as class, but appreciate the way ACKS does it.  James Spahn has done supplements for Labyrinth Lord that do the same thing, providing racial classes that are more specialized.  I'd love for ACKS to put out a class compendium that brings together all the classes from their various books.  But it seems that they're focused on other things right now.  One of our main games is OSE Advanced but using the racial classes, (i.e. not separating race & class) including some from ACKS and the Spahn book mentioned above.  I find these more interesting than just being a halfling thief or whatever, even if the halfling burglar is basically that.

I also like the short monster stat blocks, toned down abilities, morale checks and the three point alignment system.  And yes, no character sheet should ever consist of more than two sides.  I won't even play a game with a character sheet exceeding two sides.

Quote from: Persimmon on August 30, 2022, 12:49:03 AMI'd love for ACKS to put out a class compendium that brings together all the classes from their various books.  But it seems that they're focused on other things right now. 

I'd like that as well.  More specifically, I'd like to see Autarch release an OSE compatible product with a selection of race/classes designed with standard B/X rules in mind.  Obviously ACKS is B/X compatible, but the class design does include some variables based on the ACKS rules set that make it more than just a straight drop in.  I do agree that his plate is pretty full with Ascendant so probably not going to happen, but one can always hope.

If only Alex was around to read this... 

Probably because it's simple. 

Or it's easier to add to a bare bones game than re-write a more complex one.  I think a lot of OSR games are just the author's own house rules.