I'm thinking about a pano head to help with my sunrise panoramics, and was looking for some advice about which ones to look at, and how easy/hard they are to use??
Having a leveling head at the bottom can be useful to get a level surface, or else you need to precisely set the tripod leg lengths. Or you could have a geared head like arca swiss D4 with rotator on top.
I like rotators with click stops (easy to use, possible to work fast!), and then I'd recommend nodal ninja. I use a pre-production model of Nodal Ninja Ultimate "M" Series (with an EZ-leveler II at bottom), it is built around arca swiss dovetail, good price/performance (good stability, 70-200/2.8 lens no problem). The drawback with that system currently is that it is not easy to set the horizon at say 1/3 (a clickless upper rotator is coming though), I often do two-row panoramas though and then it works well. An advantage of a "true" panorama head is that you get rotation around nodal point so you can have close foreground and even make indoor panoramas without parallax errors.
If you have heavy gear (body + lens) you need really stable stuff or else you have to wait several seconds between shots for the vibrations to subside.