The Hella system has a smaller compressor that spools up fairly fast, so the delay is pretty brief.
I god fed up with trying to command attention with the "beep" "beep" of the stock VW horn, so I installed the Hella kit on the Bug. Now, folks in front of me seriously consider wearing "Depends"! :p
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car