I'd love to see some more range back in their tool kits.
Though, part of the issues with Vanguard/PT is that our Utilities are crap. I struggle to find a real meaningful upgrade to my character when it comes time to choose a utility. And none current choices really scream at me that I must have it.
As a start, I would like to see something like "Reflexive Shield" utility from Commando in Vanguard.
Threat issues aside... You can't use harpoon while out of combat. So having it as a gap closer will not work. The animation time on it also sucks. Either way, if we can't pull X because its a boss, or whatever, then Harpoon should pull us to it.