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.
Read 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.