Downed state - good or bad?

[Lucky_]

I like it. In PvE it gives you a chance to kill the monster that killed you and saving a trip back. In PvP it adds another level of strategy. If you leave a guy really low, some classes can easily kill someone at lower health and get back up. Overall I like it, but most of the time it doesn't really matter as people usually finish you off right away unless they are being attacked by someone else.

I had a moment in structured PvP when I was 1v1 on a point, and neither one of us would attack when were both low because we knew that first one to die would be the one to lose the duel.

If you find this sort of thing to "add strategic depth", then boy will you be disappointed to find out that most competitive avenues carry specific rules to forbid such behaviour, and strongly discourage it.

[Cyclone Jack]

I like it. It makes things much more interesting, especially when running in a group.