twiiii tends to look at things from a practicality standpoint. He likely has more experience with McIntosh amplifiers than any of us here. That being said, he and I often have differing opinions when it comes to application. Your speakers certainly exude quality so I bet they do sound good.
I for one have always thought the MC7270 represents the single best value in a high powered McIntosh amplifier (I've owned four). The MC150 is two generations newer than the MC7270 and honestly I've heard so little feedback on that particular power amp. I'm one of those guys that will try things in my own system versus settling on why it won't work. Over the years, I've tried all kinds of stuff that others said wouldn't sound good. In most cases, they were dead wrong. For example, I had a die hard Mc tube guy tell me that there was no way using my pair of MC240s bridged could outperform my MC275. They blew it away. No contest. So much so that I sold the MC275 about two weeks later.
When it comes to matching speakers to amplifiers, I've settled on synergy being the single most important criteria. I drove my Altecs with an MC2300 for nearly 20 years before being able to track down an MC2600 that I could purchase reasonably. Both amplifiers have excellent synergy with the Altecs. The MC2600 is the superior of the two, mainly because it's quieter - that's a good thing when driving speakers with a horn that measures a foot tall and two feet wide. Also, the MC2600 seems to control the woofer in the speaker better giving the Altecs a more robust bottom end. Over the years, I tried every McIntosh amp that came through my hands (I've had a few hundred) with the Altecs. Only the MC2600 (and my MC500) bested the MC2300. Although the MC2600 is double the power, I did run strapped MC2300s for a long time as well - it's really hard to say which is more capable there. I think they're actually very close. The fact that I just love the MC2600 has me wondering how much I might love the MC602 - after all, that's two generations newer!
Audio is a hobby where certainty is not something that can be arrived at in a thread. That's why I typically encourage folks to try stuff and see what sounds best to their ears. If I were in your shoes, I'd be excited to take delivery of the MC7270. And, no matter what anyone tells you, I'd also try the bi-amp arrangements with the two amplifiers. Forget about volume gains. Think about synergy. When you find that perfect synergy, you'll know it right away.