Well, obviously someone in the GTVA liked the Ulysses, since it managed to stay in service through the Second Great War.
I've never minded flying the Ulysses myself; while it doesn't have the blazing-fast speed of the Valkyrie, it's still the second-fastest ship available to you in FS1, and its thin profile means that you're much less likely to get hit than in something like a Herc. (The few times I've taken on enemy Ulysses...es in various campaigns have not been the most pleasant of experiences.) And damn, can that ship turn.
If I had to go head-to-head against a bunch of Dragons, my ship of choice would be the Ulysses; it's the only thing in the GTA's arsenal that even comes close to being able to match them move-for-move.