Eagle Rock Resort cabins have newly refurbished interiors, which are pretty basic but still nice. They sleep 4 with bunk beds and have a lovely porch to sit on. The bathrooms are shared but close by and fairly clean.
Eagle Rock Resort is pretty remote, having to drive over 50 miles through a National Forest from Mount Rainier, meaning the only things around are the grocery store and restaurant/bar attached to the resort. Luckily, they also have gas. I was told that I would be left a key outside the cabin. When I arrived around 6:30pm, I found my welcome packet with no key to be found. The grocery store (which also handles rentals) closes at 7pm, so by the time I realized my key was missing, I just barely caught them after closing. However, they were super friendly and I was able to eventually get a key for my cabin.
Overall, it was a fairly pleasant experience, just know going in that this cabin really is in the middle of nowhere.