I was talking to a friend yesterday about how OP the Velator is. Relatively speaking. Related my experiences belt ratting in it, and my trip with a Corvette fleet back in my former corp (we got ourselves a Cerberus, among other things). I ended up realizing: I needed to run a Guardian's Gala site in a Velator.
Well, a few hours and a whole bunch of blown up Velators later, I can confirm that I don't know how to fit a Velator to run Guardian's Gala. The right mix of fit and tactics just doesn't seem to be there. Kiting the frigates is hard, and if you set up to do it you don't have the DPS to dent the cruisers or BS. Speed tanking the frigates is pretty hopeless: there's too many of them to start with. If you put a decent tank on, you sacrifice too much DPS.
This Reaper, on the other hand...
[Reaper, Gala Runner AR] Gyrostabilizer II Gyrostabilizer II 1MN Y-S8 Compact Afterburner Tracking Computer II 280mm 'Scout' Artillery I, Republic Fleet Fusion S 280mm 'Scout' Artillery I, Republic Fleet Fusion S Warrior II x1 Republic Fleet Fusion S x1856 Optimal Range Script x1 Tracking Speed Script x1
The Reaper fits a little better for this use case. Angels are weak against explosive, so being able to select damage type is pretty essential. Small artillery has a reasonable combination of range and tracking. There's plenty of CPU on the ship, and enough grid to make things work.
(Boy do small missiles and rockets need a damage increase. They are just...sad. I would have liked to try a missile Ibis, but that wasn't happening.)
I have taken down a Guardian's Gala site in this Reaper. (Caveats: I've only done this once, only on Singularity, and a little bit more piecewise than makes an ideal demo. But I think you'll find it doable, if a bit challenging.)
Theory of Operation
Prep: Set default keep at range distance to 10K. Set default orbit distance to 2K. Load the Tracking Computer with a targeting range script and turn it on.
Frigates: Come into the site at 30K or so. As the nearest frigates come into targeting range, target them. When the nearest gets to about 2OK, go ahead and turn on the guns. When the nearest gets to a little over 10K, hit keep at range on it and turn on the AB. By now you should have enough aggro, so launch the drone on aggressive / focus fire and set it to work. Always make sure you keep the nearest frigate 10K out: if a frigate manages to lock you, you'll probably die. Other than that, it's just keep targeting and shooting at the nearest until all are gone.
Cruisers: You'll now switch to speed tanking. Switch your Tracking Computer to the Tracking Speed Script. Target the nearest three cruisers. Select the nearest Cruiser and hit orbit. Set your guns on the one you'll be orbiting. You'll probably take some damage burning in. Once you're in range you'll quit taking damage and will slowly (slowly!) grind each cruiser.
Battleship: Basically the same as the cruisers. Burn in, most likely taking a big hit on the way. Grind until done.
Skin: Loot the skin. You win.