Just finished the whole house in Hardi-plank, painted it a light khaki. Looks a hell of a lot better than my neighbors vinyl siding. Actually came out less in cost, mainly because of the trim and soffit pieces costing an incredible amount of $$$ in vinyl.
One point to consider, you get a reduction in your insurance with the cement fiberboard, it counts as an all masonry house. Plus, with the Tyvek wrap and the foam sheathing the house is a lot better insulated. You can really tell the difference in how much the AC runs.
Hanging it is a breeze, snap a line, hang a plank. No special tools needed, treat it just like wood, although it's pretty hard on table saw blades. The only real grunt work involved getting the old wood siding off and replacing all the windows.
The only thing I would do differently are the soffit vents, I used metal vent strips because I didn't realise Hardi-plank can be had with the vent strips molded in.
Took me three weeks of evenings and weekends. Materials cost was a little under 4,000$, but included some custom windows and a roof over the 14'x16' deck.