Here's how I would summarize the comparison between 1.2 and 1.3...

Unless that slight increase in weight (0.1 osy) trumps everything else for you personally, the 1.3 is a significantly better hammock material. Hands down. That's not to say the 1.2 isn't great too, because it is. This is just better.

To my knowledge, this is the lightest Nylon 6.6 based hammock specific fabric to ever be produced.

That said, as a line by line comparison, with the 1.3 you get:

1. A higher weight rating of 275 lbs with less stretch

2. Significantly better durability (particularly resistance to abrasion and thinning spots...)

3. Less UV degradation (color fade AND strength) over time

All that for +0.1 osy in weight is a good tradeoff in our opinion . Let us know if there are any other questions. Happy to help as always.