Going active is much, much, much more labor intensive, plus you need a great (expensive) measurement microphone and a steep learning curve for speaker measurement software and how to interpret the results. Active is not something I'd recommend unless you are willing to spend the months of time necessary to get good at this. Plus, with active you'd need a separate amp for every driver. And, the last but far from least issue is noise - with no passive filter in front of it, these tweeters are 105db efficient, which means you WILL hear noise from your amps via the tweeters. How bothersome that is, that's something you'll have to decide.
Staying passive saves you all that work, keeps the noise a lot lower, and gives you a crossover designed by an expert (Danny).
