In which case, I would limit your choices to what local dealers have to offer, or take a trip to a dealer that does have the Pioneer range. Are you really prepared to spend £1500 blind? Don't do it!
Over the years I've read lots of reviews of products either profssional reviews, or people's recommendations, only to listen to them personally and within moments know that it's not the right sound for me: to the extent that I couldn't live with it. So as much as I like the Pioneer/Apex combo, you really must listen to it yourself. I know other forum members who find Pioneer AVR's too sharp in the treble and they prefer a softer sound. What I call, crisp, punchy and detailed, others call fatiguing or grating.
I can't tell you what I like, but I can't tell you what you like.