New servers, hooraaaay! More bandwidth, more power.
I'm not doing history so it's hard to judge. However from my experience I can make a few comments about certain subjects.Subjects that have a large gap between SL and HL content:PhysicsMathematicsChemistryBiologyAll LanguagesSmall gap between SL and HL content:EconomicsGeographyEnglishSubjects that are hard conceptually:HL mathsHL PhysicsSubjects that are hard due to the sheer content you need to remember:EconomicsBiologyHistoryHL Chemistry (SL chem is easy)If you do HL Physics, SL Chemistry will be a breeze due to alot of the concepts already being covered in physics.