I've been shooting with a Sirui P-424S monopod and both R1/Rokinon 8mm and RS-1/Nikkor 16mm for a couple of months now, and have been getting great results, so I thought I'd share with the group.
In both cases, I'm also using RD5/EZ-Leveler II/Quick Mount Mini.
What's cool about this particular monopod is that it has feet that are wide and stable enough to hold the pod upright on level ground. (no, I wouldn't normally get further away than arm's length unless I was taking a shot of the setup!) Fully extended, the camera sits just over 6 feet in the air as seen in the attached image. The best part though, is that the feet are small enough that they don't show in the Nadir - they're entirely covered by the base/rotator/leveler, so there's only a very small Nadir patch to deal with.
Oh, and the base detaches to become a very low profile tripod if you ever need to get really close to the ground, table or whatever surface you're on.