Eder put it more eloquently than I could. I've played WC 1/2/privateer, but have only seen screenshots and pictures of the ships from WC3/WC4, and especially for WC3, it's hard for me to get past the 'flying geometric shapes' aspect. In some cases, it seems like the only tool the designers had...

I didn't like most of the WC3/4 ships after all the ships from WC 1/2/privateer, going to those boxes..... ugh I understand that it was probably a limitation on the 3D engine, but giong from smootly flowing lines and rounded curves to boxes in like... 2 years? blegh