Stealth is unpredictable, for both you and your opponent. It might provide no survival, or it might provide more than average. The expected range is roughly 0-2, actually a bit less than that. You might be an invincible target, or you might be an "easy" kill. This leads an opponent looking to make a comeback to shoot at you (risk to try and equalize cheaply), but it leads an opponent looking to stay ahead to choose an easier target (avoid risk to maintain advantage).
Though he ultimately recommended shields, I like the point he makes here about Stealth being unpredictable. I think that can work in your favor. It makes the squint more of a wild card.
If your just running shield upgrade then you opponent just adds one more hit point to his mental tally of damage he will have to roll to destroy the squint. However, if you have stealth then he has to factor in the extra dice your getting and the higher probability of rolling evades. To me that seems like a much trickier equation to resolve and thus would keep your opponents guessing more on whether or not to attack.
Bottom line, I think that stealth on a squint just makes the decision to attack more difficult than just putting a shield on would, and you can use that to your favor.