I have a high performance Mini3 and an even higher performance PPAS (LME49710/20 and LMH6321).
A PPAS could be anything, depending on the opamps, class A biasing or not, the use of isolating JFETs or not. I prefer my PPAS. It's smoother and more refined, but it doesn't have the slam of the Mini3. Both have superb details and soundstage.
I can say that the buffers used in the PPAS for sale (LMH6321) are very good, equally good to discrete diamond buffers. Regarding AD8066, I find it better sounding than AD8397 used in Mini3. (I have a Xenos amp rebuilt to almost a Mini3 with AD8066 and LMH6654 so I can compare them head to head). This should be an excelent sounding amp.
If you want to use it for longer travels, the current draw could be a problem.