I found a couple of fights against a pair of bombers. One of them is an experienced bomber pilot, and the other is an average pilot ( out of practice, but used to be devastating back in the day).
First fight, both bombers were loaded out with an inferno and supernova + four hullbusters. It was a very close fight, but after I took one bomber out, the other didn't get a chance to drop my sheild.
The second fight, one of the bombers was mounting CD's. Because this prevented me from EKing around in the gunboat, I couldn't see the bombers most of the time, let alone hit them with a razor.
I would have had trouble killing the bomber with CD's on it's own let alone with the other one there as well.
On another note, soloing gunboat in a bomber with or without CD's is always a challenge. I've only done it a handful of times against gunboat pilots worth their salt.
Against fighters you could (if flying correctly) wade through three of four fighters with a properly kitted out gunboat. They are now primarily anti-fighter weapons however flying a gunboat when people are spamming CD's at you is frustrating at the very least and normally ends in the gunboat exploding.
EDIT: I have yet to fly any gunboat with a forward gun in this mod. I am going to be setting up a Liberty Gunboat soon, as it's a ship I've always liked the look of.