1.
For PvE I think that others believe vanguard is one of the best tanks.
For PvP I think it is seen as the worst tank. Low dps and not as much survivability as the others.
For PvE dps: Not really wanted but ok.
For PvP: Assault spec maybe best dps in game
2.
For PvE: Great tank. Really enjoy it.
For PvP: I use to be shield spec and then it got crushed in 1.3. I went from 150k damage and 100k protection. To 85 to 100k damage and 100k prot. Eventually I just gave up and switched to tactics since you get +20% stun dam prot and hold the line is great for huttball. I'm still a tank and my dam went to around 160k-180k and 120k prot with healer. It may look better on the scorecard but the shield spec throws off lots of debuffs that my new toon just doesn't have. I'm very disappointed since I spent all this time trying to get war hero supercommando armor and now that I have it, it seems like vanguard is only really a dps class. I currently have 5 50 lvl toons. A vanguard tank, healer sage, healer scoundrel, dps sent, tank assassin. I also have a lvl 38 sith warrior tank. After 1.3 my vanguard tank went from my favorite pvp class to my least favorite. I'm slowly turning him into a dps and have bought two war hero pieces. In the future it would be nice if I could just trade in gear if an advanced class is getting a major overhaul like the free respecs.