What's your view of speaker crossovers?

For years I've been using a single driver now (Monacor 130AL, aluminium
cone like a Jordan). Of course it's not perfect - bass is only just
there and treble could be better. That's the deal. But nevertheless I
add ribbon tweeters (Decca) and take them away. Yes, the ribbon sounds
better but the crossover doesn't.

So, what do you guys feel rocks your boat? Are you in the camp of full
frequency response or that of total integrity (or whatever words you
feel describes a single driver)?

As a reference, the best speakers I know are panels like Magneplanar or
even better Apogee - yes they have crossovers but the sound remains the
same top to bottom in terms of delicacy, so you have the "feel" of a
single driver.