There are those who are satisfied with the general quality of AVCHD renders, and there are those who are not. I get the impression that nobody who complained before feels that the new release improves matters. The problem appears to relate to AVCHD files from specific devices.
From my devices AVCHD renders seem fine - except that there's the problem of repeated or jumpy frames where SVRT comes to a transition. That doesn't particularly surprise me - it's very hard to integrate the rendered frames with the unrendered frames at such points, and I've yet to see a program that can do it completely successfully.
Going from one iteration of a highly compressed video to another is bound to cause some quality loss. Going from a bitrate higher than that used in PD to the lower bitrate of PD is also far from ideal. Presumably there's a reason (licencing cost based??) why PD8 doesn't render at the higher rate used by certain camcorders.