I own both the Z-5500 and L1, and both have their strengths. Overall, I prefer the Bose L1, however, a modified Z-5500 5.1 surround system is very close to the Bose in sound quality, and does an outstanding job. The modification is very simple. It essentially consists of replacing the center speaker with a larger speaker with better mid range frequency response and a longer throw, thus providing outstanding mid range for vocals and instruments alike. The sub is awesome, and the satellites do an excellent job is producing crisp, clear high frequency sounds. And, the Z-5500 is 550-watts RMS and 1,100-watts peak power. There are lots of pros using this system in restaurant and nite club settings for audiences to 125 people and report incredible results.
The L1 is an outstanding system, 750-watts RMS and 1,400-watts peak power. The 24 speakers contained within the 7-foot column provides 180 degree coverage with very little falloff, even at significant distances from the speakers. This, when combined with a single sub will easily handle most audiences to 300 or more people, depending on crowd noise, venue configuration, etc... The sounds are incredibly crisp, clear and distinct, both keyboard and vocals. If you make a mistake, everyone in the venue will hear it.

Neither of these can be considered a Conventional Sound System--they're not. Some performers love them, while others claim they're just not sufficient for their purposes. The beauty of purchasing the Bose L1, however, is you can try it out for up to 45 days and if you or your audiences do not like what they hear, you can return it for a full refund--NO QUESTIONS ASKED! That's one hell of a manufacturers guarantee.
Logitech has an outstanding service department, and excellent warranty, but the returns are up to the descretion of the dealers. If something goes bad with the Z-5500 during the warranty period, give them a call and they'll send you a brand new system--NOT JUST REPLACE THE DEFECTIVE PART! And, most of the time they will send the replacement unit out the same day. The only thing you have to do is return the old unit's remote reciever--neat.
The choice is yours. You can go with a conventional sound system, which means speakers on poles and lugging heavy equipment. Or, you can take the plunge and try something unconventional.
Good Luck on whatever system you decide upon,
Gary
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Travlin' Easy