Active VS Passive speakers and, specifically, Elac Navis ARB51 as the active speaker?

What is your goal? What are you trying to achieve? Room dimension, listening habit, music and genre reference? Home theater or stereo?

Your question is very loaded. You have to specify what you need to get the answer.

+1 viethluu.  And then analysis paralysis takes hold.  This forum is already unforgiving enough, add no direction and it goes wonky fast.

Sorry for the incompleteness of the question.  I listen to jazz, rock, country.  I want to have speakers in multiple rooms: workout room, tv room, living room, bedroom, maybe even one on the patio.  listening is more passive than active.  I know I won't have great sound with this budget, but I would like to get good quality sound given the limited budget and desire to have music in multiple places.

For your broad requirements, I'd use a combination. Actives for the room you want the best SQ and passives on a switch for other rooms. Understand if you get an active speaker you won't be able to choose the amps or route the amplifier signal to other passive speakers.