I'd like to start off by saying that the sublime feel of the PS 6.0 85 is impossible to replicate, but the 2014 PS90 retains most, if not all of it.
This is as close to a "PS 6.0 90" as you're going to get. Does the 6.0 85 feel better? Yes, but by a slight margin, and you have all the benefits of being a slightly larger 90 sq inch head.
- Angus