I was in a very similar situation. I had a current model planar 2 that I upgraded with an rb330 tonearm, GT subplatter and derlin platter, JA Michell Tecnoweight and Rega Ania cart. The upgrades as a whole made the table sound amazing even if it didn't make financial sense in retrospect.
I just recently traded in that table along with every upgrade except the Ania cartridge. The trade in helped me purchase a new model planar 8 and I have no regrets what so ever. I have had the new table for less than a week and I am thrilled with the improvement in sound quality. I was also concerned about a planar 6 being a lateral move but i can confirm the planar 8 is a significant step up. With your Apheta 2 cart on a new model Planar 8 I can't imagine you being disappointed.
I just recently traded in that table along with every upgrade except the Ania cartridge. The trade in helped me purchase a new model planar 8 and I have no regrets what so ever. I have had the new table for less than a week and I am thrilled with the improvement in sound quality. I was also concerned about a planar 6 being a lateral move but i can confirm the planar 8 is a significant step up. With your Apheta 2 cart on a new model Planar 8 I can't imagine you being disappointed.