Personally, I would stay away from splines for modeling architecture. Simple primitives and a decent poly-modeler are more than enough to the challenge of building a high rise. Programs like FormZ are solid modeling programs, which are perfect for this kind of modeling, but there's a lot of overlapping polygons here... making for a dense and very inefficient mesh. My vote is to go with Cinema 4D. :o) Modeling a decent building is a lot of extruding and lofting simple geometry. Unless we're talking about modeling a Corinthian Capital the use of splines might be a bit of overkill. Still... at the end of the day, if splines get you the architecture you want, go for it. My suggestion about architectural modeling would be to get yourself a set of plans with dimensions on them, and start modeling what you see a little bit at a time. I've done a few buildings, so I can help from practical experience. It actually helps to model the same way you'd build a house or building. Start with the floor, model in the columns, put up the walls, get the roof up, throw in doors and windows... and you're done. :o) With buildings, same thing model your building footprint, extrude, slap on your columns and your exterior cladding, detail out your windows, clone them as required, build a rooftop and throw on a few details here and there... and you're done. :o) I hope that was helpful. Cheers! M

Mind Over Matter
"If you don't mind, then it don't matter."