Well after 3 weeks of pretty steady shooting panos with the Nodal Ninja I have some comments. In short, it's not strong/tall/long enough for the 20D with moderate (75mm - 100mm) telephoto lenses. It is very good with shorter lighter lenses though. Though I haven't tried it, I'm sure it's excellent with a fixed-lens point & shoot camera.
The Nodal Ninja has an upper weight limit of 3 pounds. Come to find out, this is not enough for the gear that I own and wish to use.
20D + battery - 27 oz
17-40 - 18 oz
Tamron 28-75 - 24 oz
Canon 50mm 1.8 - 5 oz
Sigma 105mm Macro - 16 oz
So the 20D with the Tamron is over weight, the 17-40 and 105mm are close. The Tamron and Sigma are long, however, which means the tilt-arm is stressed more. The 17-40 *barely* makes it, in my opinion, and the Tamron and Sigma are too heavy and the tilt-arm sags. The sag of the upright with the Tamron was very noticeable. I didn't happen to notice when I tried the Sigma. The tilt-arm slipped a lot with the Tamron, and again I didn't notice with the Sigma. With the 17-40 any sag or slippage of either arm was manageable. Though Nick states 3 pounds for a limit I'd suggest no more than 2-1/2.
I did use it for a bit with the 50mm lens, which is light and small. The NN performed flawlessly, and this combo is probably my best choice. But 50mm is too short for what I want to do.
With the short upright of the older NN model I have you simply can't tilt up enough with the 20D. The newer model is supposed fix this.
The tilt arm, even with the extender piece, is not long enough for either the Sigma or the Tamron at 75mm. At these lengths parallax is not so apparent so this isn't much of an issue as long as I plan for this.
Because of the size and weight of my equipment I wish the base were larger, much larger.
I did not find the angle degree marks to be accurate enough. The "notch" on the bases allows for some slop, I think, since it is kinda wide and slopes near the edge of the base. I would definitely prefer a thin white line right to the edge of the base.
Since the base is rather small the angle degree marks are close together. Larger diameter bases would allow more room for the angle marks, and thus it would be more accurate. I think it would also make the upper arms more stable, since these would lean less with a large base.
I find that I *really* wish it had detents. I doubt that I would choose another pano head without them.
Now that I'm done "trashing" the Nodal Ninja I want to clarify and add some things. For one, several of the things I mention are nitpicks and minor. Others would actually detract from the Nodal Ninja - for instance a larger base would make it heavier, more expensive, and less portable. Other things are mentioned because I'm an obsessive accuracy nut who goes beyond what's necessary.
Nick clearly states that the NN has a weight limit of 3 pounds. The gear that I have and wish to use is close to or more than 3 pounds. My fault and my problem, not the Nodal Ninja's. To be very clear, the Nodal Ninja is simply not for me. Otherwise I find it to be an excellent piece of equipment at an excellent price, and can highly recommend it for a camera that is lighter than mine.
I really want to do multi-row panos with my Canon 70-200 L, and there's no way the Nodal Ninja will handle that. I'll have to use my 3-way head, and I'll need to make/get some type of extension bar to move the lens back enough to get the nodal point above the center of the tripod. My 3-way head's up/down tilt point is about 1" off center, so this will introduce some parallax errors but hopefully it won't be too noticeable at the longer lengths. Would this inch make a difference at 200mm? If I'm careful? [Answer from a couple gurus: No, it won't make a difference if I'm careful not to include anything too close, and that's unlikely because of the short DoF at longer lens lengths.]
Otherwise, for the wide-angle (and short telephoto) lenses, I'm thinking that the Kaidan QuickPan Spherical would be my choice, but it's about $400. That's a lot. There's always the possibility that I could build one out of wood and/or aluminum, but there are a few design issues - particularly with detents - that will be a problem.
Anyway, if you're using light equipment, I can strongly recommend the Nodal Ninja.
Also, if you do panos, I strongly recommend PTAssembler, Enblend, and Autostitch. PTGUI and Smartblend that are choices for PTA and Enblend respectively.