I agree with others. Don’t pay attention to the volume "number" on the front. Each device can have different logarithmic volume curves and represent them with completely different numbers.
That being said, I can see your comments making sense. The PM14 is very nice (as is many of Marantz devices), but overall Marantz equipment is voiced warm. The PM14 may be warmer sounding than the 8005. In my experience, a warmer sounding equipment will have a much more laid back midbass/midrange. Even though the power output is there, it just does not have a visceral impact of sound. The sound will not come across with a lot of "attack" or "authority" because the slew of the waveforms are too slow. Think of this as a comparison between someone slapping you with a bare hand and someone slapping you with a ski glove on. The slap happens with the same speed. It’s just the ski glove comes across very subdued.
verdantaudio had some suggestions to tweak your system by using a different speaker (such as the bright/fast KEF) or using a different source. You can also increase the speed by using a lot of silver or silver-plated wiring (interconnects, power cords, speaker cable). This will increase the speed/attack of the warm sounding PM14, but it never ends up that great. I have worked with warm equipment in my system and have tried many things to fix that "too slow / too laid back" issue. The problem is that once it passes through a very warm/slow device, such as the Marantz, there is absolutely no way to fix that back to a "neutral" sound. It’s like putting a band aid on a problem. You are better off switching the warm device with something else.
Your comment about the speakers "jumping to attention" with the PM8005 makes sense. Even though the power is the same, equipment that is more neutral or high resolution will have a faster attack and more of that "jump to attention" factor. The sound would just be more "there" in comparison to a very warm Marantz device.
So, in my opinion, I think you should look at selling the Marantz devices and putting in a more neutral or high resolution integrated. The Music Fidelity M5si would be a good choice. It is definitely not warm sounding and actually has more power than either of your Marantz integrateds (which is good because you generally want a larger power supply). There are other choices, of course. If you sold both the PM8005 and PM14S, you might have enough to go for the larger M6si.
That being said, I can see your comments making sense. The PM14 is very nice (as is many of Marantz devices), but overall Marantz equipment is voiced warm. The PM14 may be warmer sounding than the 8005. In my experience, a warmer sounding equipment will have a much more laid back midbass/midrange. Even though the power output is there, it just does not have a visceral impact of sound. The sound will not come across with a lot of "attack" or "authority" because the slew of the waveforms are too slow. Think of this as a comparison between someone slapping you with a bare hand and someone slapping you with a ski glove on. The slap happens with the same speed. It’s just the ski glove comes across very subdued.
verdantaudio had some suggestions to tweak your system by using a different speaker (such as the bright/fast KEF) or using a different source. You can also increase the speed by using a lot of silver or silver-plated wiring (interconnects, power cords, speaker cable). This will increase the speed/attack of the warm sounding PM14, but it never ends up that great. I have worked with warm equipment in my system and have tried many things to fix that "too slow / too laid back" issue. The problem is that once it passes through a very warm/slow device, such as the Marantz, there is absolutely no way to fix that back to a "neutral" sound. It’s like putting a band aid on a problem. You are better off switching the warm device with something else.
Your comment about the speakers "jumping to attention" with the PM8005 makes sense. Even though the power is the same, equipment that is more neutral or high resolution will have a faster attack and more of that "jump to attention" factor. The sound would just be more "there" in comparison to a very warm Marantz device.
So, in my opinion, I think you should look at selling the Marantz devices and putting in a more neutral or high resolution integrated. The Music Fidelity M5si would be a good choice. It is definitely not warm sounding and actually has more power than either of your Marantz integrateds (which is good because you generally want a larger power supply). There are other choices, of course. If you sold both the PM8005 and PM14S, you might have enough to go for the larger M6si.