Was handed a standard Warsphere as part of a Tau fleet defending against a Chaos planetary assault on Saturday. Didn't realize that it automatically passed AAF! Anyhow, being a Defense @$%×s when a Carnage puts you in its broadside.
Similar to the Nicassar Caravans. At max though costs 250 pts compared to only 200. Less shields and turrets, less manoeuvrability too. But twice the hits, nearly twice the firepower, longer range, and potentially faster. Not to mention the boarding and planetary assault bonuses. Probably worth that 50 pts.