I would prefer that if there is a radar, everyone is on it. The radar isn't an insta-win. You still have to KILL the people you are seeing. You could suck *** and have a Blackbird but die more often because you are going STRAIGHT for the enemy.
Permanent Radar, no doubt. Although I dont really mind ghost and can actually count the times I've played against an entire ghost using team on one hand, those few matches were beyond boring and slow and from my personal experience, most campers that I've come across were ghost users.