Fabrizio,
Regarding other add-ons....
We have also some plan about curtain walls but I don't know if a "specific" add-on for this purpose could be interesting (who knows?) maybe we could delay just a bit ArchiWall and add this code into it...
A curtain walling add-on would be good, possibly with a parametric window generator as well. ArchiDesigner was an add-on that generated parametric windows for up to version 7, as you are probably well aware. The ArchiCAD library curtain wall objects are good but not quite smart enough, for example you cannot create a faceted curved curtain wall, although of course curved curtain walling is ususaly faceted. AutoCAD ADT has a specific curtain wall tool I believe.
Regarding ArchiStair, I think its great, am enjoying using the v9 copy at last. The editable hotspots are really useful to sort out irregular shapes for top and bottom treads. As I mentioned before handrail heights on landings in the UK have to be different from on the flights of stairs, so ideally there would be a hotspot in 3D on landing handrails, allowing you to adjust the heights.
Also an ArchiStair wish list item....
As it is possible to build your own toolbars and access all the commands in ArchiCAD 9 (more or less), you can add the "Show ArchiStair pallet" command to a toolbar, but there is no icon for it. Therefore you get the whole lot in words which is too long. Can the ArchiStair api provide icons for the menus so that you can put an Architsair icon on your toolbar (assuming this is possible in ArchiCAD). The same would go for all the other Cigraph add-ons.
