I get they need to nerf for PVP and WVW but really, I leveling thief for exploration and stealth skip those pesky add. Hope they didn't nerf PVE to the ground but here we are.
For me personally my build are
I use Celestial, preferred this and with some boon duration, maybe help a bit
http://gw2skills.net/editor/?PagAQVlFwAZXsQmJeASCPCA-zxIYVFDTjqAA-e
Using rifle dodge stealth, and signet of agility to restore endurance once its out. Use hide in the shadow which not only give stealth but also vigor thank to trait so endurance regen quicker. Shadow refuge and shadow meld no need to be explain just give stealth, and smoke screen give smoke field which you can leap or in my case, blast with my bow. Rotate all these skill and you should be able to stay on long enough, I think I can stay over a min with this, not work for PVP or WVW which I don't mind, as long as I can explore uninterrupted, that's fine by me.