evaluating ressources saving between differents families

Even the Megawizard usually shows the sizes, and I believe the user guides do to. They're not always 100% accurate, but pretty close. (The user guide charts can't show every option, so they're based off specific settings. The Megawizard usually shows guesstimates in the lower left corner, but since it hasn't actually gone through synthesis, there's no way to know for sure.) In the end when evaluating size and/or performance, designers have a bunch of test projects that they throw something into and give a quick run. I still do schematics for this, and probably end up making a new one every other week to see something else. (If you have a lot of multiplier requirements, you're going to see significant area savings in the DSP blocks...) But shouldn't you be targetins Cyclone III, which has DSP blocks in it too, or is this an older board you have?