In architectural work we used it all of the time, and on models that were around for decades. It works real well structurally, takes paint, of course it costs a whole lot less.
My advice is use a straight edge, and change your blades often(you'll need a lot of blades, go to an office supply store(like OfficeMax or Staples) get a box of 100 you'll need them). A dull blade is a real pain when cutting foamcore. Use Elmer's glue, drafter's tape or blue tape to hold parts while they set.
As long as you take care of the finished model, you'll have no problems. A lot of people think you have to do all sorts of fancy things, and spend a lot of money in the modeling world. That's just not true, modeling is up to your own creativity. If you find something works then keep doing it. As long as your happy who cares what other people think.