The films looked similar, but the Platinum 4x films were ever so slightly thinner -- especially at the max 'stretch'. There was something unusual, however. The longest platinum tubes were not as long as the maximum Dawn Pro tubes.
Juice details. Both juices pH-adjusted to 7.6 with 5% citric acid solution. For platinum: 9 grams. For DP: 8 grams 1000 grams water 50 grams detergent 6 grams BLM
Loops: 32" top-string loops from SecureLine 3/16" cotton cord.
The platinum juice required more citric acid than the DP solution.
All in all both juices worked well. I'd give the edge to the Dawn Pro solution, but that could be normal random variation. More comparisons need to be done.
Here are some other pictures from the session.