Yeah I got mine last week, and installed it right away. I got version 3.1, so it was super-simple to install. No soldering, just a couple cables to disconnect and re-connect to the board.
In fact, it probably took me longer to open the Saturn case than it took to install the board.
No problems, it worked right from the get-go. My only beef is that it only supports CDI, CCD+IMG+SUB, MDS+MDF, and ISO. So if you have your game rips in another format, you'll have to convert them into one of these formats for it to recognize.
Oh, and of course, it would be nice if it had a GUI to select the games rather than the button on the board, but I heard there are plans for that in the future.
All-in-all, it runs like a dream. Loading seems quicker and the unit is silent, 2 big wins for this thing. I picked up this Saturn for practically nothing because it had a busted drive, so upgrading to the Rhea was perfect for it.