Managed to go head to head with an Syndicate frigate called an Eldorado. I haven't done a full stat check on it, but it does have a slightly larger cargo space and carries about 25% more marines than the Orca I was flying, and has an extra cannon slot. Apparently, the Eldorado is an Imperial design(I guess the Syndicate pirated it?), so you can't exactly buy it as the Empire is always hostile. After breaking it's shields and punching the hull a bit, I sent boarders over and captured it, despite it having more marines and an "alarming" threat rating.
While towing it back to LaGardia(the nearest friendly station), another Syndicate Eldorado and a freaking
cruiser(I didn't catch the design name, my best guess was a Poseidon) with a threat rating of "impossible" pop in and target me, preventing me from docking. Specifically, they taunted me over the comms, which means they spawned in just to kill me. Worse, the ship I was hauling was too large to be towed at PTE speeds, so I couldn't run without abandoning the prize. Then I looked at the the scanner map, and noticed it suddenly got very busy with blue(friendly-ish neutral) dots. I turned right back around and started firing at the cruiser.
While my weapons did more than I expected, a cruiser is still two size categories larger than a frigate. When it had punched through most of my shielding, I felt I had made a big mistake. At the least I'd have to ditch my prize and run for my life. At the worst, I wouldn't get very far... Then as I made another pass at the cruiser, I noticed I wasn't the only fighting it. The thing was getting hammered from all sides by all those blue dots. Within seconds, the cruiser's shields were completely gone on all sides. A few seconds more, and it was no more. And I leveled up.
After that, everyone else seemed to have buggered off, leaving me to deal with the other Eldorado. Since I was exhausted from the cruiser, that fight was a little tougher than the one I was still towing. I took out it's starboard shields and got it's hull down to about ~25% before I ran out of energy and it started to PTE. I couldn't catch up without ditching the prize, so I fired a torpedo after it. It hit on the unshielded starboard hull, destroying it as it escaped.
Then I brought the prize back to the station and dropped it into my garage. I'll work up some extra money to outfit it before I use it.
Starpoint Gemini II.
I looked up the stat differences between the Orca and Eldorado. The Eldorado has better shielding and more guns. It can send over one less marine per transport but that's barely an issue. The main difference is less energy for guns and less ammo for heavy weapons. However, I don't think the stat page is up-to-date, since it says the Orca does not have a hangar when mine actually does.