I really like the Zephyr now. I'd normally go with Mountain because of the attack skills but this really seems interesting. In campaign mode, those three skills are a really nice way to start, and you can make up for the damage by researching damage abilities to make it versatile and a really effective all-rounder.
Sure, you take the damage penalty, but for the probably relatively short time I've been facing AI I've noticed that the zephyr can save lives. I don't know where my balloons and warlocks would be without it. Even the shamans are often just too late with healing my army themselves.
Regarding the Mountain Dragon... the HP penalty seems to fit well. High damage output, low capability of taking hits. Unlike a typical "tank", I noticed that using the Mountain Dragon is not a matter of just rushing in and letting go... it's a good one to stay with your army, close to your shamans or whatever source of healing is nearby. Just don't go alone. I... kinda regret that every single time :P
Can't say much about the Sabre as I have little experience using that specific dragon.
