Honestly, I think my true ideal would be the 3e Unearthed Arcana rule of "Player's Roll Everything" where they also make saving rolls against weapon attacks with a static DC of 10+monster attack bonus. When I GM I have enough to worry about without having to roll half a dozen attack rolls each turn of combat, the players only have to manage their characters.
I use a similar rule, but if you want the probabilities to be exactly the same it's actually 11+bonus, not 10+
I write all things, attack bonuses, AC, spell saves, as +5 [16]. This way anyone can make the roll. I can have players make attack rolls, players make defense saving throws, or even monsters making attack saves, all depending on what works best at that instance.
As for saving throws, I prefer the more ad-hoc method of just listing things a character is good at saving (+4) or bad at saving (-4) versus a target number based on level. There aren't fixed categories. For example, magic users get a bonus versus Spells whereas an elf gets bonuses versus Enchantments.
I also treat armor as a saving throw versus damage but that's an entirely different thing.