I truly do not feel that the loss of the defense that stealth provides is a good idea. While it is true that a hero can get a decent amount of defense by taking various defensive powers, please keep in mind that by doing so they are losing power selections of other types, and therefore tends to become more of a roleplaying reason (though I do know some may want to min/max, but all of my characters have different powers all based on how I roleplay them). I feel that Stealth's defense should not decrease because you attack, and if it does, it should be for a very short time-perhaps like the 4 seconds mentioned by another at the most. To help show why I feel this way (and I only feel it should keep its defenses because of the basis of the game, it is a Super Hero one and in comics, those that attack while concealed or using stealth are rarely spotted unless they want to, or make a bad mistake.
The following is my view on Stealth and other defensive powers in other pools to help illustrate why I believe it should keep its defense. I am most assuredly not saying that these other defense powers should lose anything at all, simply showing a correlation:
Stealth: I really feel that making stealth lose more of its defense is uncalled for. If the other powers decrease, then lower it likewise, but please think of this point of view:
--I view stealth as something like Batman, lunging out of the shadows, striking a villain that who may know he's there, isn't quite as sure where to shoot or punch and so Bats is safe. He attacks, and then is again in the shadows. Another example would be Nightcrawler, teleporting from the shadows or from somewhere hard to see, attacking and then gone again, with the bad guys only able to aim in the direction of where they hear the "bamf" sound happen after they've been hit. Stealth will, to me, lose its entire usefulness if it loses all defensive bonuses because you attack (which so far seems to be fixed, but I still disagree with it losing some defense when you attack).
My blaster uses it as her main defense, though she has several; and I consider her to be semi-invisible (like the Predator from the movies and that comic too) as she steps slightly out of reality to stay safe while attacking. Other characters I've seen, from Ninja-type or assassin type characters to demonic or vampiric based stealth users would have explanations that wouldn't allow for the defense granted by stealth to leave them because they attack (shadows darken on the victim; the attack is too fast for them to know where they were hit from, etc.) It just seems to be a large factor to a power set that could very well be made worthless with its singular offensively used power made so less effective when many that take the powers need all the defense they can get. (again, I'm glad they only decreased it instead of removing its benefit while attacking, but does it really need to be decreased more?). You get to your enemy with invisibility, and then stealthfully attack him/her, and as reinforcements arrive you phase into the shadows and retreat...just an example of story and play-based use.
My second thought for this is: If the reason for losing stealth's defenses altogether is because you've attacked and now can be seen, then what of the other powers? Shouldn't you lose your defense from Combat Jumping when there's not enough room to effectively jump, or when you don't even jump at all by pressing the spacebar? Hasten has the most powerful reason in this game to lose it's defense bonus as its primary use for most characters is to recharge their abilities faster, but if you're moving faster, shouldn't you be harder to hit still? Leadership wouldn't help you much unless you are in a team that has you as the team leader, and has been together long enough to trust your orders. Basically what I am trying to say is that what you may end up doing to Stealth could just as easily apply to every other defense-based power in the game. I don't really feel it should happen to any of them, aside from whatever general adjustment you make.
To me, Combat Jumping works because even in a small area, the person bounces from object to object to try and give them that defensive edge (insert your favorite bounce-person from comic here) as they use their agility to do so even in very small areas. The true Leader in comics shouts his orders with a quick reason and people benefit from it. "I've fought these before! Quickly, cover me and that blaster and use electricity!" Hover also would only really apply any bonus if you were constantly moving around (according to a tactical book on helicopter piloting; "a hovering helicopter can make a perfect high-level attack platform, but is also a sitting duck") but in the comics, our hero and even our villains glide to the side while in the air to avoid that attack. Even Hasten has its use as a defense to those that play the game for fun as they think of their character moving with that extra speed they've trained for to avoid punches, or simply dodges a hail of gunfire as the bullets look slow to them since they can run and move at super speeds.
As for losing your actual difficulty to draw aggro...well I could see how perhaps your range could be effected; as snipers shoot from ranges while camoflauged for a reason, so perhaps it could allow more aggro when attacking with it than it did before and be only safe from larger aggro at distances.
Just some things to keep in mind, and I hope that they help.
