I have, so far, had great durability with just 105 alone (no base at all, except for almost 2 month old Aquawax). In the rain, the beads are some of the tightest and smallest I've ever seen, including Zaino. So far, the 1 coat of 105 I have on the car, is showing absolutely no signs of degradation after being outside 24/7, going on 1 month.
105 on top of AIO should work fine. As said, if you want the absolute best possible performance from 105, use the PBA first. Even without the PBA (as in my case), I've noticed zero performnce problems, so I really feel like I'm not giving up anything by not using the PBA first. It's still a little early to tell for sure about final performance, but all indications look like the 105 is there for a long time! :2thumbs:
