I have Dead Money DLC and one of my builds is a high luck one, so I was able to gain the voucher, wich means that I have unlimited access to Med-X, Buffout and Steady.
Also, OWB adds Battle Brew to the equation, wich grants +35 DR and you have Slasher, wich grants another +25 DR and can be used along with Med-X.
So imagine if you have Logan's Loophole + Chemist + Cardiac Arrest + Day Tripper.
Cardiac Arrest = with 8 END you are imune to poison and gain +50% in healing items
Chemist = doubles the time a drug works
Day Tripper = +33% drug duration
Logan's Loophole = immune to drug addiction
With 75 points in medicine and survival most items works at extremelly very good levels
The equation's result = God Mode!
Who needs stats at 100% with those? Just buy a lot of Steady and all the weapons in the game are turned into accurate snipers. With Battle Brew + Slasher + Med-X you gain +85 DR on top of your armor DT. With Chemist this +85 DR will last at least for two minutes due to Slasher duration and after that +60 DR for 8 minutes. I'm not counting Day Tripper, so add +33%. Repeat ad nauseum or until you are out of drugs.
This isn't too much?
Also, why there's this talk about "all enemies will level slower and the game will be easy" if the player is capped at level 30? Enemies spawn with fixed stats based on what level the player is on the game and only after this, they level based on the player stats if they are allowed to do that. Most of the time the respawns are from another more stronger version of the enemy. But guess what, even if they level and you go to Sierra Madre at level 20 like the DLC recommends, the Ghost People will be at least in level 40 and they will scale at +1 per level, so in level 30 they will be at the maximum allowed level for them, 50. In fact, the next respawn of a Ghost People, like the ones in front of the Police Station, will be a stronger version with maximum level.
OWB and HH follows the same rule, so before level 30 all enemies will be in their full levels contrary to popular belief.
If you go to the DLCs below the recommended level, regular enemies will spawn more weaker, but in the end they will all reach their maximum level and stats way sooner than level 30.
Beyond level 30 is the player who actually becomes more stronger and the game becomes more easier.