OSE kinda sucks huh?
I get what the OSR/TSR movements want to do and their design philosophies, but you can keep those philosophies up while updating some bad design choices.
Objectively worse than progressive AC, since it's mathematically the same but less straightforward to calculate.
Some of them have a d6 probability, others a percentile. Why? Why can't they just put them all in percentage?
>Races as class
Just stupid and awkward. You can reduce races to something as simple as ability caps or modifiers, or just a single racial feature (like "Dwarves can't have starting Dex above 12 or starting Con below 12. Dwarves can roll to recognize hidden architectural elements like trapdoors and sliding walls").
There's a lot of little thing that just seem holdouts from the old games for the sake of nostalgia. I get that nostalgia is the whole point, but if you want to sell an old game as a new product, you could at least update the elements that have proven faulty in hindsight.