I use the rules in my sig for FO3. It extends game play... you are weak enough that you think twice, and sometimes three times, before engaging anything. However, I should note that I don't actually follow the main quest anymore as a quest, rather than as something that gives me new enemies every once in a while, so I'm not picking up extra XP all over the place. I also play on Hard for all DiD characters; so you should be able to get some mileage out of this style.
This is a very reasonable way of thinking and dealing with the turbo-leveling in F3. However - I′m not that good at harder settings. I usually play on normal difficulty and that′s quite enough. Perhaps it would be a good idea that the levelprogression speed is scaleable depending on the difficulty you choose.
Given the level cap at 30. Or there could be an option at the start of game, where you can choose between slow/normal/fast. Something for Fallout 4?
"3. Have fun/ Die a lot!"
good one