Not a fan of the canon Cardassian vessels. Though I've seen some much nicer non-canon designs and fan designed Cardassian vessels.
I don't like how they got one ship class (not counting Keldon, which apparently was just a Galor mounted with a big-ass cloaking device, or the Hideki) for ten years' worth of appearances.
We've had the Romulans and Klingons for 40 years and we have around 5 for the Romulans and maybe 8 for the Klingons. Non-Fed races don't get much starship love. I would have liked to see more variety in the space forces of these bigger powers.