Just an update for those that are interested!
My p1000 arrived a few days ago and I'm very pleased with the improvement, though it has thrown up a couple of problems.
Firstly the good stuff! It's incredibly punchy - drums and bass kicks sound awsome and it has that classy hifi sound I was always craving. The midrange is extremely crisp and detailed, voices and instruments like pianos and acoustic guitars cut through my room like a razor, yet sound completely natural and not at all harsh. Bass seems a bit more powerful and with much more control and an added warmth, though maybe not as much I originally hoped for.
Now the problems! The "in your face" midrange can be quite hard on the ears after a while, and the treble can sound very harsh with low quality sources. Which is a bit of a problem for me since 90% of my usage is for watching digital tv, which is very compressed and tinny. The fact that I have quite bright sounding speakers doesn't help at all! I also find myself craving a bit more bass, and often end up ignoring pure direct mode and reaching for the tone controls on my denon. The amp also seems to be buzzing slightly. Maybe this is normal, but worryingly the tweeters and mid/bass drivers also have a quiet buzz when silent - my denon never used to do this. Also one of the speakers is buzzing slightly louder than the other. I re-wired the amp and speakers and it improved slightly, but it's still there.
Overall I'm pleased with the increase in sound quality for the money, but I now have a much bigger urge to sort out the pre amp stage with a decent processor and some decent DACs. I'll definately do some demoing soon to see how much of an improvement this will give me.