1. When I fast traveled to the GNR plaza after a reset, there were simply way too many brotherhood soldiers standing outside protecting it (20-25?). I feel they could be reduced a bit for the high spawn setting.
2. Large numbers of spawns were added to certain zones where the player should be fighting solo, most notably the Pitt. In the steelyard, I ran out of ammo rather quickly (you only get about 100 rounds for an assault rifle). I entered a building with only melee weapons at my disposal, saw 20 trogs shred 2 wildmen and then pour over me and my auto axe. 1 poorly-equipped player vs 20 trogs = epic loss. The other DLC zone I visited, Anchorage, seemed more reasonable.
3. Hordes of enclave soldiers spawn during "Take it Back!". The after crossing the bridge and making a right turn, the area at the end of the back-street is a nightmare. Either my game would crash, or I would be gunned down by the enclave. The ~7 lyons' pride members get mowed down rather quickly in that encounter. It seems that no brotherhood troops were added to help compensate for the enclave spawns. However, that would contribute more to the CTD-ness of the quest lol.
4. Super Mutant Gargantuans give rather parsimonious exp. Lol, on another note I was about to watch an epic battle between the BoS and a gargantuan, but an ini setting I was testing froze the game and the monster didnt spawn when I visited the area after reloading .