As a tac who often PUGs I almost always stealth, I'd prefer to not to but a good stealth and a bad stealth are different things. I can kill the close left, far left and far right 4 out of 5 times without agroing any of the mobs. The close right is a run for your life situation.. I avoid that.
It completely amazes me watching idiots run around the room shooting turrets and other random enemies and then walking right by the saboteurs because they aren't shooting back... unbelievable. These are the same people that bolt into an area in round 2 and start the timer off in round 3 with 2 people still dead.
I never use stealth tbh. Never have.
I'm a tac and I always use the fire team kit with mk xi maco gear with a mk xii polaron pulsewave. I normally do pretty well, managing to nail 2 single handedly with the rest of the team getting the other two.
I always hit my buffs just prior to going in. Everything including suppressing fire and tac initiative. I then select the pulsewave, jump into fps mode and go run in. When I see the first big cluster of enemies I will hit the secondary mode and maybe throw in a plasma grenade. The suppressing fire will debuff their speed just enough for me to sprint past and get to the saboteur. As long as I'm quick I can get into a position where I can hit the sabo without taking flanking fire from the mobs and my damage buffs will still be up. It might take 5 or 6 hits but with the maco shield capacitor power you can pretty much last twice as long.
Once the sabo goes down I run like a bat out of hell back to the nearest hallway and hide behind the pillar just long enough for my shields to come back up.
Rinse repeat as required.
I normally take out at least two and don't die. This is a pretty risky tactic, you either pull it off in spectacular fashion or fall at the first hurdle.