1) They are not very stealthy; and
2) They are fragile as heck.
The upshot of those two things is that they sure as hell better be able to kill what they uncloak to shoot at because chances are they won't survive the counter-blow. And since they can't currently warp around cloaked it means that either the enemy gets a chance to react to the arriving Stealth Bomber or you have to set up ahead of time and wait for a viable target to wander by. So typical use of the ships is to hunt industrials or frigate in low traffic areas. Hardly a glamorous life if you ask me.
Recognizing that Stealth Bombers are not in a happy place, CCP Chronotis has been batting around ideas to change them:
We are looking into improving and focusing bombers to be more bomber like with a more focused target group and bonuses which compliment this role much better.The line "[t]his allows them to inflict a high amount of alpha damage on larger targets and be serious threat to them" is telling; they want Stealth Bombers to be able to attack cruisers and bigger and not be a frigate killer using cruise missiles.
The role of a stealthy glass cannon is to ambush and deliver a large amount of firepower through volleys of torpedoes onto large targets. To facilitate this new role better, the bonuses and some of the attributes are being changed appropriately.
So what are we looking at changing exactly?
1. Bombers will be able to fit covert ops cloak
However they will have a 30 second cloak reactivation delay. This means they can warp in cloaked and better surprise their targets in a true ambush. However once they are committed to the fight, they will not be able to recloak quickly as a drawback so choosing the right time to strike is essential.
2. Bombers will be able to fit and use siege launchers and fire torpedoes.
This allows them to inflict a high amount of alpha damage on larger targets and be serious threat to them. In gangs with other ships and available strategies will add significant damage to the fleet. They will no longer be able to fit cruise launchers as a result.
3. Bombers will gain bonuses to torpedoes
Each racial bomber will gain a damage bonus to their racial damage torpedoes (EM = amarr, Explosive = minmatar, Kinetic = caldari, thermal = gallente) and a torpedo explosion velocity bonus so they can better hit large targets which are moving in addition to a torpedo velocity bonus increasing the range and speed of the attack.
Its an interesting tact and a hard one at that. How do you create a frigate based hull capable of delivering significant blows to a well tanked crusier or battleship without unbalancing the ship entirely? Obviously almost all targets will require more than three torpedoes to be destroyed and since they are close range weapons, the bomber will be very vulnerable after uncloaking to attack.
Of course, one could argue that a team of stealth bombers with covert ops cloaks could be very dangerous. Even two might take out a tech 1 cruiser quickly with bonused torpedoes... but does that mean a single bomber is essentially useless on its own? That seems counterproductive.
If I had the design reigns what I would do for Stealth Bombers is simple: allow bombs to be used in low sec. That is to say, make them true bombers and forget the cruise missile and torpedo madness that only leads down a rabbit hole of not enough tank and not enough damage.
If bombs were allowed in low sec, the Stealth Bomber could not only be a big damage dealer with its alpha strike bombs, it could utilize its ECM and Energy Neutralizer bombs as well causing much havoc and hilarity. Well trained pilots with a bombing run could turn the tide of battle, or set up a superior number force for disaster with a well placed neut bomb. I know it can currently do these things in 0.0, but the smaller gang mechanics in low sec would benefit more from its abilities in my opinion.
They would be balanced by the fact that the bombs are more involved in aiming and shooting and can hurt your own fleet's ships if they are in the area of effect. And with no covert ops cloak, you have a chance to see them coming.