I think the problem with the AT Pro in this type of comparison is that given the parameters, price indirectly becomes an important factor.
And as good as the AT Pro is, it's not worth it's current asking price.
Right now, the base street price for a new AT Pro is $550 or so. I think most of us can agree that much of that price is for the Garrett name and not it's metal detecting capability.
From a capability perspective, I think the AT Pro should have a base street price of $350 (and as a result, the AT Max should be priced $450). I think many metal detector hobbyists (and not casual consumers) would agree with this overall sentiment. Honestly. I think those prices should be lower, but I know Garrett has great warranty service and their name is worth a premium...although not THAT much of a premium, in my book. Of course, Garrett fully deserves to get very penny they can from the market, so I'm not blaming Garrett for doing this.
Garrett isn't the only company that does thism either. Fisher does it with their higher end detectors, like the F75 (+, Ltd, etc.). The difference is, a used F75 is notably cheaper than a used AT Max (the Garrett rough counterpart to the Fisher F75). This is despite the fact that there are probably far more used AT Maxs on the secondary market than F75.