They are definitely different. I believe the PH-1 behaves a lot more like a "vintage phaser." It will distort if you feed it too much signal (sort of like how a BF-2 does) and it is has a bit more warmth and organic feel.
The PH-1R solves a few of the problems with the PH-1 and has quite a bit more headroom and feels "more stable" when I play it. I have silver screw versions of both. I like the tone of the PH-1 slightly more but I think the PH-1R is friendlier for most people.