Welcome Nadeem to the HTF.
I am moving your thread to the Receivers/Separates/Pre-amps/Pre-Pros section. You will get a better response to your question there.
I’ve been Yamaha’s 7-channel systems for 8 years now, and I love it. The extra front speakers add a lot to the soundfield effects. I went without them for a period (i.e., using the standard 5-speaker set-up), and it made a significant difference. I was happy to get the extra speakers back.
Yamaha has specific placement preferences for the front effects speakers, but I have found placement to be forgiving. I don’t have mine as high or as far behind the front mains as Yamaha recommendations, but it sounds great in spite of that.
My personal opinion, is that Yamaha DSP algorythms in general are quite top notch.
I personally liked the sound fields of the Yamaha RX-V793 receiver I had a while ago (Dolby Digital only, *before* DTS...), better than that of the Sony TA-E9000ES pre amp/processor I have now.