help focal 726v to 836v?

I own the 836v and have only heard a 726v once; however, I think you will find it to be a substantial upgrade. The 800 series have better cabinets and lower frequency extension due to the bottom port. Plus, I think the true 3-way design is superior to the 2-1/2 way design. I almost went with the 816v, but the superior instrument separation on the 836v compelled my to go big or go home.

I would anticipate your integrated sounding great with it. I have an Integra 50.1 receiver that sounds great and a Yaqin MC-30L integrated tube amplifier rated at 50 wpc in ultralinear mode that sounds fantastic.

I have heard the top Aria locally and I don't think they are significantly superior to the Chorus 800 series. There are some excellent deals on the discontinued speakers making them a much high value in my opinion.

On paper the cabinets and configuration appear to be virtually identical leaving the driver material as the most significant difference. As much as I enjoyed listening to the flagship Aria I don't think it was significantly better than the Chorus series drivers. Maybe more listening and a direct A/B would yield different results.