I've got one as well, just got it actually. The handle is definitely different. I see the other (non guinness branded) stout faucets have an extra piece at the top which allows for a normal screw on handle. I am thinking that if we could get ahold of whatever that piece is called (anybody?) we could add it to our guinness stout faucets, and be able to use any handle we want. The Guinness handle is nice (mine broke during shipping...Ive been glueing/puttying/sanding/painting it back together, since I got it off craigslist), but a little big for my taste.
If anyone has any info, I'd love to hear it!