Q:
how good is GS?
The phantasm on GS may be easy to dodge in 1v1s, but gets considerably harder to avoid in team fights, and has great cleave.
As far kitten goes, it is significantly better than Pistol’s interrupt (Being AoE and a knockback. Controlling where your opponent is standing gives you a huge amount of power in a fight. Also, being knocked down requires time to get back up), and Chaos Storm is (While a great interrupt), not reliable for that purpose given that Daze is applied randomly.
I recently dropped the staff for greatsword because I got sick of using the staff for nothing but Chaos Storm and Phase Retreat. The Phantasm on it does good single target damage if the opponent has a lot of conditions, it tracks properly, doesn’t get blocked, and happens to crit on the single hit it has. Overall, recently I’ve started viewing the Staff as a crutch for most mesmer builds that is no longer a neccessity.
Basically,
The GS isn’t the best weapon in the world for 1v1s, because as you’ve said, has some pretty obvious telegraphs about avoiding the best skills it has. It shines in team fights where the opponent can’t devote all their attention to you though, and you actually get to land the iBerserkers and Illusionary Wave.
Also, remember, only one person need stand on point to prevent capping/decapping. If you’ve got a bunker already there doing their job, get some kittening distance and nuke from off point.