The Ursa is after all an older design. It is fairly mediocre in FS2 (the Sekhmet is equal or better in almost every way) but was great for its time in FS1. As was said earlier, the Medusa is weaker and can't carry harbingers even if it's actual capacity is only slightly less, and it wasn't all that much faster or more maneuverable anyway. The Ursa also has the extra primary weapon mount.
Indeed. The Ursa was
the bomber to fear in FS1. In FS2, the times and technology have changed, and the Ursa is more obsolete. It doesnt even compare with the Medusa, though. Not at all, it's far more powerful.
You people forget to keep things in context. This game isnt and never was about ships being as fast as a Perseus with as much power as an Ursa. Balance, and playability play a major role in what makes FS so great. Many of you forget that.
And I might add that the way this thread has proceeded is ridiculous. A good example of what's wrong with this place these days. 
Indeed again. Cut the flaming. (Cobra, if you have nothing nice to say, or disagree, either say nothing, or say something politely.) This kind of behaviour is what I'd expect from elementary schoolers. Either grow up, or shut up. More flaming will end up with this thread being locked. It's far too diseased as it is to cut out the cancer and hope to start anew.