It never hurts to try they say.
I'm running active and would never go back. It's so much fun wasting time by sitting on your driveway listening and tuning.
But here you have the power issue. Is getting another amp out of the question?
While the mids might be power hungry, I haven't seen too many tweeters that require gobs of power. You might try and get a little amp just for tweets and bridge the 5ch to mids.
On the other hand if you are not really into tuning and faking around with your system, leave it on passives.

Anyhow, I'm all for active.