Mass T1 Bombers are always viable
Not always easy to use or the best solution, but always viable, might not even need a mass of them, a few into the enemy air/naval production to wipe out all engies and poof, free win right there.
But you need to know that shields+flak can make your life horrible. As can ASF clouds if your enemy knows how to use them.
T1 aa isn't really a problem as you can kill static cost effective enough and mobile is too slow to protect a large area. T2 mobile flak is cheap and effective though so if there's two of those things protected by a mobile shield/cybran shield that's far too ineffective to kill with T1 bombers. Cybran frigates and cruisers(especially Seraphim, cybran not so much) are also really good at killing T1 bombers.
If you're trying to kill AA with them, the stun from the Aeon can be really handy but if you just want to kill buildings, the cybran one has 300 damage. Seraphim has the best AoE.