TIE Bombers are like real word WWII CAS Aircraft. Great when there is no opposition around, little more than targets when there are. Personally, taking a light, manuverable TIE Fighter, designed with the idea of "speed is armour" and then slowing it down, weighting it down and giving it no appreciable defensive increase gives your average TIE Bomber crew the same life expectancy of a IL-2 gunner.
A-Wings, well, better I suppose but I don't see the point of shielding if there isn't enough to actually make a squat of difference. Surely the tempermental and cramped shield generators could be omitted, the ship would be less of a repair headache, and the extra power could be used to make the A-Wing even more of a hotrod. After all, its designed for Recce and as an Interceptor, not heavy attacks, so it needs speed not shields that are ineffective anyway.
As I said, Assault Gunboat all the way. Failing that a Missle Boat, but I dislike having only one gun. Strip out the missiles, give me a crap load of laser cannons and ion cannons (Quad Laser + Turret , Quad Ions) and make it a Gunboat and i'd love it. The Skipray is close but its too corvette-eee for me, trades too much speed for firepower.