I also like that I can upgrade piece by piece as I get more money with a separate amp.
In your price range and chosing a very good measured active speaker by a well known manufacturer (Genelec, Neumann, ...) an upgrade wouldn't make sense. Those speakers contain amps perfectly designed for each driver - having just the right amount of power and sporting THD numbers well below those of the driver. They also contain safety features helping to protect the drivers from destruction due to overload.
Eventually it's the performance of the speaker
including its active electronics which counts. Just look at the measurements of the Genelec and Neumann speakers here at ASR or at Sound & Recording and then try to find a passive speaker in the same price range which beats them - chances are almost nil. That's why I claim that updates make no sense, and it's the reason why professionals rely almost exclusively on active speakers if accurate sound is required.