Upgrading from. Rega Planar 6 to a Planar 8??

Put a Lyra Delos on the P10 and it will be anything but bright and brittle. The Lowly Delos is better than any Hana cartridge and the RB3000 is one of the best tonearms made. Ultimately, all of these tables need to be on an isolation platform. I agree with you on Rega cartridges. 

Pivetta, that is a sideways step. Be patient and save more. Rega makes a good table. Wait and get a Planar 10, an improvement you will notice, and put a Lyra Delos on it!