I used the Pentax K-7 with a 14mm f2.8 and 85mm f1.4 lens. You can probably see the stark contrast between shots as field of view and depth of field attributes are so different between the two lenses. I also tried some fast and slow shutter speed control with water features, which was fun. Seeing as tripods are not allowed there, I just put my camera on my camera bag for longer exposures and it worked out nicely.
I also had a polarizing filter that fits my 85mm that I experimented a bit with too. I was able to get a 3 second exposure with the filter on. This is just a small sampling of the 400 or so photos I took, but my site (and bandwidth) are not unlimited, so I am just showing you a few of my favorites. The garden is worth the small admission fee they charge, so I would suggest checking it out if you are in the Northern Illinois area.