On the subject of the Octo tipping over:
Yes it's an issue, especially when you play a lot of hilly courses. I frequently find myself standing on a lie with no flat surface within 30'. (Bear in mind that my home course is Diamond X, and I also enjoy playing a lot of mountainous courses here in Montana.) On flat ground you shouldn't have much of a problem, so I understand how it can sound silly.
When setting the pack down on a sloped surface, you can angle it so that the long side of the base is going uphill-to-downhill. For even more severe slopes, your best shot is to just lay the pack down on its back. (However, that also means that if it's muddy out, the mud gets on your back.) So you can manage the problem, but it is something extra to think about that I never had to worry about when I was using the old Fade tourney bag.
As a side conversation:
There are 2 design factors that make the Octo tip over easily. First, the base is pretty narrow in the front-to-back direction, which holds the main compartment discs tight to your back. Earlier in the thread there's a picture of the Octo in profile next to a Disc Mahal, and you can see that the Octo is noticeably narrower. 2nd thing is that the hydration sleeve is high and tight to your back. That's a very ergonomic place to carry the water weight, but it also raises the center of mass of the pack.
These factors that make the bag tip over easily (narrow base, high center of mass) are also the reason that the Octo is so easy to carry. Anyone who knows much about backpacking will tell you that proper weight distribution inside your pack can reduce a lot of unnecessary strain on your body. In that sense, the tippy-ness of the Octo isn't a mistake/flaw, but rather it's a design compromise. Lack of stability on sloped surfaces is a trade-off that makes the pack more comfortable.