First of all, you might find the posts on page 1 of this thread about SSR helpful, then you can ask questions as well:
https://www.disboards.com/threads/ssr-lovers-and-owners-part-4.3948180/
One difference that may or may not be significant to you is the bus transportation at the treehouses. The bus from the treehouses takes you to the Grandstand bus stop, and you transfer there to the regular SSR buses to the parks, DS, other SSR pools, etc. On the way back you transfer again. At OKW, your bus stop will be on the internal loop, so no transfer needed if you’re going to the parks.
I’ve always wanted to stay in the treehouses, but to me it would be for a visit that wasn’t heavy on parks. They’re kind of isolated, although in beautiful surroundings!