They both look like good options, thanks. 696 looks quite a bit like the planetx free ranger!
Yes, the Free Ranger is a 696. It's a very popular frame. I've seen at least a dozen companies selling versions of it.
The 696 has slightly more road- like geometry than the 707. Although it can fit huge tires, I likely would have had a lot of type overlap. I went with the 707 because it's a bit longer in front. That should also make it more stable on rough trails.
(Still painting and building mine so no feedback on the ride yet. )