I too loved them both and you've hit the nail on the head when you say MB is meditative, incense-like and warmer whereas HK gives an instant green blast followed by earthy, woody tones.
I would have both but longevity is a real issue, particularly as these are natural perfumes. I get a maximum of 2 hours from MB, less for HK. That addictive green blast lasts maybe 15 minutes or so and then I'm left feeling slightly cheated.
It doesn't help that I'm intensely allergic to oakmoss, either!
Secondly, the price is excessive, costing around £80 for 33ml. That's too rich, even for my blood. I don't feel that I'm getting value for money.
I'm currently awaiting a sample order from Slumberhouse, whom I hope will be just as good.