Punkuk,
Be careful what you wish for....
Most good high-efficiency setups(re: horns) can be ruthlessly revealing of other components and poorly recorded material - as most punk & rock is/was. They can be so revealing that much material will seem almost unlistenable until you learn to fully accept bad recordings.
The move from 90db, mid-efficency/mid-wattage, 3-way system to 97dB/6 watt system has left a large swath of my punk and rock recordings unused. They just plain sound horrible - too much compression, far too tinny, poor dynamics, etc. very wart is held under a microscope. I can only think it gets worse as efficiency goes up into the 100dB range.
The jump to horns isn't as simple as simply getting the speakers. Source components, amps/preamps, will also be held to the microscope. Previously unheard hum in components and your AC line will stand out like a sore thumb. So, you might also have to get a new amp and/or preamp plus some line filtration, too.
High-eff is awesome, but it comes at a premium. Not always in cost, but in attention to minute details many times not necessary with less efficient systems. The payoff is worth it to many of us, but do not underestimate the journey.