They look cool, attacking yoru enemy out of range sounds cool, but they do a pathetic amount of damage and the resources you spend building them can get you A LOT more firepower in other vessels.
Nothing damages static defenses and orbital structures like Bombers do. With all orbital buildings both tactical and logistical using VeryHeavy armor, the Phase Stabilizer/Phase Jump Inhibitor/Regeneration Bays/Frigate Factory/Defense Platforms you're using for buying time for and putting up and/or supporting a fleet defense, will all go down soon without even scratching the Bombers or their Cruiser Carriers who are camping out at the edge of the sector.
But Hangar Defenses can deploy Fighter Squadrons. Fighters are more effective and lethal against Bombers than even flak is, even if you count the cost & supply of fielding them vs. that of flak. What's more, they can defend all over the gravity well while flaks can only shoot them when they come in for attack runs. If the enemy brought along flaks themselves, it doesn't matter since the Fighters are playing defensive already and can just avoid the flak.
Although the Bomber alpha-strike may end up killing the Fighters' Hangars, their attack will be put off-line for the next ~2 minutes, helping the survival of the remaining structures until a fleet arrives. After the Bombers are down, the Fighters can attack LR Frigates until(and if) they get killed, and scramble to knock out scouts in between battles.
the only downside is the (slow) phase jump speed, but then again its ALOT faster then going from planet 2 planet
This is with the basic Phase Stabilizers you get at Tier 5. At Tier 7, just prior to Returning Armada, they get upgraded with Enhanced Tunneling so as to achieve faster speeds in phase space.
b4 people start talking about.. and what if he destroys the gate???
As long as the ships have entered phase space, they'll land safely whether the enemy kills the Phase Stabilizer or not. They'll blow up one rather expensive piece of equipment, but they won't survive to celebrate it.
having the tech to see anyone and anything phase jump gives u plenty of time to react and get ready for a jump
This is Highly Attuned Sensors, a Tier 8 'super ability'. The tech level may not go that high, and of course you have Returning Armada on the same tier.
Still, the Vasari get the technology to see 1 jump away(Phase Space Monitoring) at Tier 1, and the tech to see 2 jumps away(Enhanced Sensors) at Tier 4. An enemy approaching your empire from 2 jumps away should be enough warning to initiate a Stabilizer jump provided your fleet is already at a Phase Stabilizer planet.