I have seen a lot of these built. I actually sat in one, and it was quite nice. At one time, this chair was so popular that the builder's even had their own little blog or forum, although I couldn't find it.
formatting link
a few of the posts on that page and you can get a feel for the chair and its popularity.
Some guys made these for inside sitting or reading chairs. Modifications I remember seeing were raising the chair height, the parallel leg surfaces were thinned out with scroll work, the armrests were a bit shorter and a bit less wide, and the splats were straightened, thinned and had some scroll work on them. The finished product looked like a fancy "Mission" style mixed with some of the design elements of the 1800s English oak furniture.
Nice cushions were made for the seat, and with the carved (jigsaw/ bandsaw scrollwork) backs, no one would have recognized it as a modified Adirondack chair.
Some of it looked pretty damn good.
Plans are free.
Robert