Ranting question

I was doing the dragon lair mission with a group.
One of the dragons dropped a yellow unique shield for me.
However, my group didnt wait and entered the portal before I got it.

My question, how good could that shield be?
Are there places with better uniques items later on?
How long will it take before I see another shield like that?
Is life fair?
Why guild wars is annoying in that aspect!?
Can they fix it? (Having a mechanic that people wont loose items just because their group jumped into portal)

It's not exactly a unique as the game defines a unique weapon, but without any specific stats like max or requirements I couldn't give you any price range at all. Even if you identified it it could still be a terrible shield...them's the breaks. Don't worry, with the new update you'll find plenty of gold shields. Try to find better teams though.