Most high SPL drivers in sealed or reflex boxes have F3s around 80-100 Hz; hornloading the rear wave can take that down to 40-60 Hz. That's good, but system SPL remains at the the raw direct radiating SPL of the driver, around 95-100dB/watt.

Horn loading the front wave instead allows both lowering of F3 and raising of broadband SPL by 10 to 15dB on average. The downside to front-loaded horns is that to make them long enough to impact the bass they usually are folded, which can limit their high-frequency bandwidth, although that's not the case in my DR horns.